Author: "Institut Pprime (PPRIME)" - Searchworks@Jio Institute Digital Library Search Results

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2,505 results on '"Institut Pprime (PPRIME)"'

1. Internal stress development during the curing of an expoxy, validation by fibre microbuckling prediction

Author: DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Institut Pprime (PPRIME) ; CNRS - Université de Poitiers - ENSMA, Jochum, Christian, Grandidier, Jean-Claude, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Institut Pprime (PPRIME) ; CNRS - Université de Poitiers - ENSMA, Jochum, Christian, and Grandidier, Jean-Claude
Abstract: International audience

2. cure multiphysics couplings EFFECTS ON THE DYNAMIC BEHAVIOUR OF A THICK EPOXY

Author: DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, DFMS ; Laboratoire de combustion et de détonique (LCD) ; CNRS - CNRS - Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM) ; CNRS - Institut National Polytechnique de Grenoble (INPG) - CNRS - Institut National Polytechnique de Grenoble (INPG) - Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Laboratoire de combustion et de détonique (LCD) ; CNRS, Institut Pprime (PPRIME) ; CNRS - Université de Poitiers - ENSMA, Jochum, Christian, Arrigoni, Michel, Boustie, M., Grandidier, Jean-Claude, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, DFMS ; Laboratoire de combustion et de détonique (LCD) ; CNRS - CNRS - Laboratoire de thermodynamique et physico-chimie métallurgiques (LTPCM) ; CNRS - Institut National Polytechnique de Grenoble (INPG) - CNRS - Institut National Polytechnique de Grenoble (INPG) - Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Laboratoire de combustion et de détonique (LCD) ; CNRS, Institut Pprime (PPRIME) ; CNRS - Université de Poitiers - ENSMA, Jochum, Christian, Arrigoni, Michel, Boustie, M., and Grandidier, Jean-Claude
Abstract: International audience

3. Coupling numerical and experimental methods to characterise the mechanical behaviour of the $Mona\ Lisa$: a method to enhance the conservation of panel paintings

Author: Riparbelli, L., Dionisi-Vici, P., Mazzanti, P., Brémand, F., Dupré, J.C., Fioravanti, M., Goli, G., Helfer, T., Hesser, F., Jullien, D., Mandron, P., Ravaud, E., Togni, M., Uzielli, L., Badel, E., Gril, J., Department of Agriculture, Food, Environment and Forestry (DAGRI), Università degli Studi di Firenze = University of Florence (UniFI), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Photomécanique et analyse expérimentale en Mécanique des solides (PEM), Département Génie Mécanique et Systèmes Complexes (GMSC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Bois (BOIS), Laboratoire de Mécanique et Génie Civil (LMGC), Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM), Ateliers d'Enghien, Paris, Centre de recherche et de restauration des musées de France (C2RMF), Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Physiologie Intégratives de l’Arbre en environnement Fluctuant (PIAF), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Clermont Auvergne (UCA), Institut Pascal (IP), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national polytechnique Clermont Auvergne (INP Clermont Auvergne), and Université Clermont Auvergne (UCA)-Université Clermont Auvergne (UCA)
Subjects: [SPI]Engineering Sciences [physics], numerical simulation, conservation of panel paintings, non-invasive experimental measurements, Mona Lisa, FEM modelling
Abstract: International audience; A numerical FEM (Finite Element Method) model was implemented to represent the mechanical state of the wooden panel of the Mona Lisa, as it is conserved in its exhibition case, and constrained in its auxiliary frame. The model is based on the integration of advanced numerical analysis and various experimental examinations carried out non-invasively on the artwork by the authors during over 15 years. This includes visual, microscopic and X-ray observations together with mechanical measurements and monitoring of panel deformations and constraining external forces. In addition to the development of non-invasive techniques to characterise the mechanical properties of the panel, the FEM model reliably evaluated the strains and stresses generated in the panel by the various actions it experiences. The paper consists of the following parts: (i) a short summary of the experimental measurements and other observations, (ii) a detailed description of the FEM numerical model, of the hypotheses it is based on, and of its advantages and limits, (iii) the main results obtained by running the model. This includes the identification of local strains and stresses, the location of most critical areas, an evaluation of the risk that the existing ancient crack may propagate, and an evaluation of safe ranges for the forces acting on the wooden panel, (iv) the validation criteria for such results, and (v) a discussion about the significance of the mechanical model.
Published: 2023

4. Model reduction of radiative heat transfer by a hierarchical radiosity method

Author: Mickaël Le Bohec, Denis Lemonnier, Didier Saury, Convection, Optimisation, Systèmes Thermiques (COST ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique [Poitiers] (ISAE-ENSMA), Institut universitaire des systèmes thermiques industriels (IUSTI), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)
Subjects: radiosity, Numerical Analysis, multiscale, model reduction, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], radiative heat transfer, Condensed Matter Physics, Approximation
Abstract: International audience; Radiative heat transfer in buildings can be determined through the resolution of the radiosity equations. This technique requires the evaluation of geometric couplings between the elements of the scene called view factors. Obtaining them is particularly challenging, especially when obstructions are involved. In addition, the system to be solved can be cumbersome, since each surface is likely to interact with all the others and the number of nodes involved in the description of a complex scene is large. We present a solution method that refines the mesh of a scene while simultaneously constructing a representation at different scales of the view factors between the contributing elements, to avoid calculating all the transfers at the highest resolution. It thus considerably reduces the calculation time and makes the tool suitable with a routine use in a design perspective.
Published: 2022

5. Two-Phase Flow, Heat and Mass Transfer and Tracer Transport to the Atmosphere from Underground Nuclear Cavities Through Fractured Porous Media

Author: Aliaksei Pazdniakou, Valeri Mourzenko, Jean-François Thovert, Pierre M. Adler, Eric Pili, Sorbonne Université (SU), Combustion Hétérogène et milieu poreux (CH ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), CEA Le Ripault (CEA Le Ripault), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), and This work was done in the framework of the CEA‐Sorbonne Université collaboration CAJ_19-84/C35513 led by Eric Pili and Pierre M. Adler. The authors thank Charles Carrigan and an anonymous referee for reviewing the manuscript, as well as Martin Kalinowski for editorial handling.
Subjects: [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.AUTO]Engineering Sciences [physics]/Automatic, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Geophysics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Geochemistry and Petrology, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph]
Abstract: International audience; Underground nuclear explosions generate non-isothermal two-phase flow, heat and mass transfer, and tracer transport through fractured porous media. The governing equations of these coupled phenomena on the Darcy scale are presented and the corresponding numerical code is briefly described. Two configurations are considered. In the first one, the damaged zone generated by the explosion is replaced by equivalent macroscopic boundary conditions at the bottom of the medium. Vapor condensation at distance from this zone plays a crucial role and slows down the tracer transport to the ground surface, while the presence of hot liquid water and of hot rubble particles in it accelerates it. In the second configuration, the damaged zone itself is treated as a porous medium with specific properties and is integrated in the simulation domain. Several regions can be distinguished with different properties, such as the chimney, the cavity, the solidified magma, the fractured porous medium, and the intact porous medium. Phase change, heat transfer and tracer transport can be detailed in these regions and at the boundaries between them. Among the most important conclusions, the role of phase change, of the thermal properties and therefore of the temperature, is pointed out.
Published: 2022

6. Guided-Mode Resonator Coupled with Nanocrystal Intraband Absorption

Author: Khalili, Adrien, Weis, Mateusz, Mizrahi, Simon Gwénaël, Chu, Audrey, Dang, Tung Huu, Abadie, Claire, Gréboval, Charlie, Dabard, Corentin, Prado, Yoann, Xu, Xiang Zhen, Péronne, Emmanuel, Livache, Clément, Ithurria, Sandrine, Patriarche, Gilles, Ramade, Julien, Vincent, Grégory, Boschetto, Davide, Lhuillier, Emmanuel, Physico-chimie et dynamique des surfaces (INSP-E6), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), DOTA, ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Laboratoire de Physique et d'Etude des Matériaux (UMR 8213) (LPEM), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Nanostructures et optique (INSP-E4), Los Alamos National Laboratory (LANL), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ANR-19-CE24-0022,COPIN,Détecteur plasmonique à nanoCristaux colloïdaux: une nouvelle filière pour l'OPtoélectronique INfrarouge(2019), ANR-19-CE09-0017,FRONTAL,Nanocristaux Colloïdaux Dopés Infrarouges(2019), ANR-19-CE09-0026,GRaSkop,Tuning Giant Rashba Spin-Orbit Coupling in Polar Single Layer Transition Metal Dichalcogenides(2019), ANR-18-CE30-0023,IPER-Nano2,Nanocristaux de perovskite inorganique pour la nanophotonique(2018), ANR-21-CE24-0012,BRIGHT,Diode électroluminescente infrarouge brillante par exaltation du couplage lumière-matière(2021), ANR-21-CE09-0029,MixDFerro,Heterostructures à dimensions mixtes sous contrôle ferroélectrique 2D(2021), ANR-20-ASTR-0008,NITquantum,Design et fabrication d'un plan focal dans le proche infrarouge à base de nanocrisrtaux(2020), European Project: 756225,blackQD, and European Project: 853049,ne2dem
Subjects: intraband absorption, optical resonator, mid-infrared, mercury chalcogenides, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Electrical and Electronic Engineering, doped nanocrystals, Atomic and Molecular Physics, and Optics, Biotechnology, Electronic, Optical and Magnetic Materials
Abstract: International audience; Intraband absorption in doped nanocrystals offers an interesting alternative to narrow band gap materials to explore mid infrared optoelectronic device designs. However, the performance of such device clearly lags behind the ones relying on intrinsic materials. Livache et al. have proposed a dye sensitized approach to overcome the limitations observed from intraband materials (high dark current, slow response, low activation energy), where the intraband absorber is coupled to an undoped material which takes care of the charge conduction. Here, we unveil the coupling between both materials using mid-infrared transient reflectivity (TR) measurement. We show that hybrid material displays a unique feature in the TR signal that we attribute to a charge transfer and for which the dynamic matches the hopping time. We then developed a strategy to enhance the photodetection performances of the hybrid material by coupling for the first time intraband absorption to a light resonator. The latter is used to enhance the absorption by a factor 4 and enables an increase of the operating temperature by 80 K compared to the reference device. The obtained device matches the performance of best devices relying on intraband absorption.
Published: 2022

7. Electrochemical noise diagnostics of PEM fuel cell stack for micro-cogeneration application

Author: J. P. Poirot-Crouvezier, Serguei Martemianov, A. Gervex, P. Lagonotte, A. Thomas, Département de l'électricité et de l'hydrogène dans les transports (DEHT), Laboratoire d'Innovation pour les Technologies des Energies Nouvelles et les nanomatériaux (LITEN), Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de L'Energie Solaire (INES), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, 020209 energy, Nuclear engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Proton exchange membrane fuel cell, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 7. Clean energy, Cogeneration, Electrochemical noise, Stack (abstract data type), 0202 electrical engineering, electronic engineering, information engineering, Electrochemistry, General Materials Science, Electrical and Electronic Engineering, 0210 nano-technology, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract: International audience; Electrochemical noise (EN) generated by a 3500 W PEM fuel cell stack (50 cells) has been measured during micro-cogeneration durability tests. The experiments have been provided during long term campaign of measurements (more than 1200 h and 100 h have been analyzed) in well controlled operational conditions following The U.S. Department of Energy (DOE) recommendations. The micro-cogeneration operation mode involves two different regimes, one at 5 A (0.02 A.cm-²) and the other 99 A (0.45 A.cm-²). Thus, recorded signals are non-stationary, under dynamic load and specific data treatment procedure has been developed to overcome this difficulty. For both currents robust and stable statistical noise descriptors have been obtained based on Power Spectral Density (PSD) in the frequency range 0.01 Hz < f < 103 Hz. The noise signature of these currents involves two fractional noises (1 / f α) with different slopes α and pronounced peaks, at the characteristic frequency f = 1.6 Hz. The obtained noise signature is similar to the one obtained previously with the same type of the stack under stationary operation mode. It was demonstrated that noise signature varies slightly during stack operation. It seems that the observed evolution of the noise signature is related with reversible phenomena because after sudden interruption of the stack operation the PSD spectra return back to its initial shape. The proposed methodology of data treatment demonstrates that EN can be used as a tool for diagnostics of possible faults in long-term operation of electrochemical sources of energy under non-stationary conditions.
Published: 2021

8. Chemical redistribution and change in crystal lattice parameters during stress relaxation annealing of the AD730 superalloy

Author: Malik Durand, Jonathan Cormier, Fabien Paumier, Shyam Katnagallu, Aparna Saksena, Paraskevas Kontis, Florence Pettinari-Sturmel, Muriel Hantcherli, Jean-Michel Franchet, Christian Dumont, Nathalie Bozzolo, Centre de Mise en Forme des Matériaux (CEMEF), Mines Paris - PSL (École nationale supérieure des mines de Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Physique et Propriétés des Nanostructures PPNa (PPNa), Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Gesellschaft, Physique de la Plasticité et Métallurgie (CEMES-PPM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Safran Tech, Aubert & Duval, Chaire OPALE, and ANR-14-CHIN-0002,OPALE,Optimisation des propriétés mécaniques d'alliages aéronautiques par le contrôle de la microstructure issue de la mise en forme(2014)
Subjects: Atom probe tomography, Polymers and Plastics, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Metals and Alloys, Ceramics and Composites, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Dislocations, Stress relaxation, Pipe diffusion, Electronic, Optical and Magnetic Materials, γ/γ′ lattice misfit, X-ray diffraction, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract: International audience; The present study aims to understand the underlying mechanisms of macroscopic contraction that occurs in γ/γ′ nickel based superalloys submitted to isothermal annealing and resulting in stress relaxation retardation. Samples of the AD730TM alloy were characterized at different scales using dilatometry, X-Ray Diffraction (XRD) with in-situ heating, Electron Channeling Contrast Imaging (ECCI) in the Scanning Electron Microscope (SEM), conventional Transmission Electron Microscopy (TEM) and Atom Probe Tomography (APT). APT analyses revealed chemical composition changes in both the γ matrix and the γ′ hardening precipitates during annealing at 760°C after sub-solvus solution heat treatment. These chemical alterations lead to a decrease of the lattice parameters of both phases, which was captured by XRD analyses. The macroscopic volume contraction is shown to be mainly governed by that decrease in the lattice parameters. In addition, from APT analyses, the chemical alterations seem to be promoted by diffusion of solutes such as Cr, Co and Fe, along dislocations occurring under relaxation testing conditions.
Published: 2022

9. A three-step, three-gamma model for the numerical modeling of the critical height of the propagation of semi-confined detonation waves

Author: Taileb, Said, Rougon, E., Robin, Vincent, Rodriguez, Vincent, Vidal, Pierre, Lau-Chapdelaine, Shem, Melguizo-Gavilanes, J., Chinnayya, Ashwin, Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Structures de flammes et Combustion (CT ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Royal Military College of Canada, and Détonique (DETO )
Subjects: [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment
Abstract: International audience
Published: 2022

10. Experimental investigation of oscillating flow characteristics at the exit of a stacked mesh grid regenerator

Author: Jean-Christophe Valière, Hélène Bailliet, Islam A. Ramadan, Roberval (Roberval), Université de Technologie de Compiègne (UTC), Acoustique, Aérodynamique, Turbulence (2AT ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Materials science, Acoustics and Ultrasonics, 020209 energy, Flow (psychology), [SPI.MECA.VIBR]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Vibrations [physics.class-ph], Reynolds number, 02 engineering and technology, Particle displacement, Mechanics, Dissipation, Vorticity, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Physics::Fluid Dynamics, symbols.namesake, Amplitude, 020401 chemical engineering, Arts and Humanities (miscellaneous), Particle image velocimetry, [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], 0202 electrical engineering, electronic engineering, information engineering, symbols, Strouhal number, 0204 chemical engineering, ComputingMilieux_MISCELLANEOUS
Abstract: The aim of this study is to investigate the oscillating flow velocity field at the exit of different stacked mesh grid regenerators using Particle Image Velocimetry measurements. Twelve different experimental cases are discussed, yielding oscillating flow fields at the exit of four kinds of regenerators for different acoustic levels. The regenerators are classified according to the mesh wire size to viscous penetration depth ratio and according to the method of stacking the mesh grids. Based on the analysis of the vorticity fields at the exit of the regenerator, three groups of flow patterns are identified. This classification is correctly verified by using the Reynolds number (based on the acoustic amplitude and wire diameter) and the Strouhal number (based on the acoustic displacement amplitude and wire diameter). The characteristics of the fluctuating velocity components are investigated for these various flow patterns. The critical Reynolds number, past which the flow is highly dissipative, is determined. The dissipation timescale is investigated and the quasi-steady approximation is found to be valid for the analysis of the oscillating flow at the exit of the regenerator mesh.
Published: 2021

11. Towards a better understanding of the high-temperature oxidation of MAX phase Cr2AlC

Author: A. Zuber, V. Gauthier-Brunet, J. Roger, J. Gonzalez-Julian, T. Ouisse, S. Dubois, Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Composites Thermostructuraux (LCTS), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut de Chimie du CNRS (INC)-Snecma-SAFRAN group-Centre National de la Recherche Scientifique (CNRS), Computational Materials Engineering, Institute of Minerals Engineering, Rheinisch-Westfälische Technische Hochschule Aachen University (RWTH), Laboratoire des matériaux et du génie physique (LMGP ), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Université Grenoble Alpes (UGA), ANR-18-EURE-0010,INTREE,Poitiers Graduate School on physico-chemical properties of INTerfaces for AeRonautic, Energy and Environment(2018), and European Project: 740415,NFRP-2016-2017-1,IL TROVATORE
Subjects: [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Single crystal, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], [SPI.AUTO]Engineering Sciences [physics]/Automatic, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Thermodynamic calculations, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Cr2AlC, Materials Chemistry, Ceramics and Composites, ddc:660, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Microstructure, High-temperature oxidation
Abstract: Journal of the European Ceramic Society 45(5), 2089-2096 (2021). doi:10.1016/j.jeurceramsoc.2021.12.057, Published by Elsevier Science, Amsterdam [u.a.]
Published: 2022

12. Influence of surface radiation on the transition to unsteadiness for a natural convection flow in a differentially heated cavity

Author: Paul Chorin, Denis Lemonnier, Didier Saury, Florian Moreau, Yann Billaud, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique [Poitiers] (ISAE-ENSMA), Convection, Optimisation, Systèmes Thermiques (COST ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: Surface (mathematics), Numerical Analysis, Materials science, Natural convection, Natural convection flow, 02 engineering and technology, Square cavity, Mechanics, Radiation, Condensed Matter Physics, 01 natural sciences, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, Physics::Fluid Dynamics, 020303 mechanical engineering & transports, 0203 mechanical engineering, 0103 physical sciences, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Adiabatic process, ComputingMilieux_MISCELLANEOUS
Abstract: International audience; The influence of surface radiation on the transition to the unsteady state in natural convection is studied numerically. The configuration of the differentially heated square cavity with adiabatic horizontal walls is chosen to generate an internal natural convection flow. It is known that radiative transfers reduce the temperature difference between the adiabatic walls, which consequently reduces the thermal stratification of the central zone and increases the velocity flow. Many studies have focused on the stationary regime, but few of them have investigated the transition to unsteady flow. For this purpose, the effect of the wall emissivity on the critical Rayleigh number and the associated critical frequency was studied for a given cavity length. The cavity length and mean temperature of isothermal walls are set for the whole study. The results show that all these values are between the values obtained without radiation and those obtained for perfectly conducting horizontal walls. The critical Rayleigh number decreases with emissivity while the associated frequency increases. Moreover, the symmetry of fluctuating properties of the flow is changed when the radiation is taken into account.
Published: 2020

13. Oxidation mechanisms in bulk Ti2AlC: Influence of the grain size

Author: Wenbo Yu, Bertrand Levraut, Sylvain Dubois, Maxime Vallet, V. Gauthier-Brunet, Centre d'élaboration de matériaux et d'études structurales (CEMES), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie de Toulouse (ICT-FR 2599), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), and This work was financially supported by the Fundamental Research Funds for the Central Universities (M19JB100020)
Subjects: Materials science, Diffusion, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], chemistry.chemical_element, Ti2AlC, 02 engineering and technology, 01 natural sciences, Oxygen, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Stress (mechanics), [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0103 physical sciences, Materials Chemistry, MAX phases, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Shrinkage, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 010302 applied physics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Grain size, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Volume (thermodynamics), chemistry, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Ceramics and Composites, 0210 nano-technology, Oxidation mechanism, Layer (electronics)
Abstract: International audience; In this work, oxidation mechanisms were studied in fine-grained (FG) and coarse-grained (CG) Ti2AlC bulk samples. Results showed that the oxidation kinetics are controlled by the grain size of Ti2AlC. Bigger are the grains, faster is the oxidation. A dense and protective Al2O3 layer forms at the surface of FG-Ti2AlC samples while for the CG-Ti2AlC samples, a thick TiO2 layer forms on top of a discontinuous Al2O3. CG-Ti2AlC was observed to simultaneously transform into Ti3AlC2 and TiC instead of being directly transformed into TiC. This transformation result in the following crystallographically sandwich-like structure: (0001) Ti2AlC // (0001) Ti3AlC2 // (111) TiC. The volume shrinkage associated to this transformation produces elongated holes that are partially filled by α-Al2O3. The stress caused by the volume shrinkage generates cracks at the surface, which makes the oxygen inwards diffusion easier and thus worsens the oxidation resistance the CG-Ti2AlC bulk.
Published: 2020

14. Sliding mode control applied to a square-back Ahmed body

Author: Franck Kerhervé, Jean-Pierre Richard, Wafik Abassi, Laurent Keirsbulck, Marc Lippert, Maxime Feingesicht, Baptiste Plumjeau, Camila Chovet, Andrey Polyakov, Jean-Marc Foucaut, Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 (LAMIH), Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Centre National de la Recherche Scientifique (CNRS), Chalmers University of Technology [Göteborg], Turbulence Incompressible et Contrôle (TIC ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Finite-time control and estimation for distributed systems (VALSE), Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Ecole Centrale de Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Ecole Centrale de Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique des Fluides de Lille – Kampé de Fériet - UMR 9014 (LMFL), Ecole Centrale de Lille-ONERA-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Centre National de la Recherche Scientifique (CNRS)-INSA Institut National des Sciences Appliquées Hauts-de-France (INSA Hauts-De-France), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 (CRIStAL), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Centrale Lille, Laboratoire de Mécanique de Lille - FRE 3723 (LML), Université de Lille, Sciences et Technologies-Centrale Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Automatique, de Mécanique et d'Informatique industrielles et Humaines - UMR 8201 [LAMIH], Turbulence Incompressible et Contrôle [TIC ], Finite-time control and estimation for distributed systems [VALSE], Laboratoire de Mécanique des Fluides de Lille – Kampé de Fériet - UMR 9014 [LMFL], Institut Pprime [PPRIME], Centre de Recherche en Informatique, Signal et Automatique de Lille - UMR 9189 [CRIStAL], and Laboratoire de Mécanique de Lille - FRE 3723 [LML]
Subjects: Computer science, bilinear time-delay model, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Sliding mode control, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, External flow, [SPI]Engineering Sciences [physics], flow control, sliding mode control, drag reduction unsteadiness of separated flows, 0203 mechanical engineering, Control theory, 0103 physical sciences, Aerodynamic drag, Trailing edge, ComputingMilieux_MISCELLANEOUS, Mathematical Physics, Mechanics, Lift (force), Flow control (fluid), 020303 mechanical engineering & transports, Particle image velocimetry, Drag
Abstract: International audience; We consider the first closed-loop separation control experiment on an Ahmed body using a robust, model-based strategy called "sliding mode control" (SMC). The goal is to reduce and further maintain the aerodynamic drag of the square-back Ahmed body flow at Re h = 9 × 10 4 (based on the body height). This study also investigates the practical feasibility of this approach which shows a great promise for industrial applications. The flow is manipulated by a slotted jet placed on the top trailing edge, combined with a predefined angle direction, and sensed by a drag balance. Base pressure and lift measurements are also obtained in real-time. The interaction between the air jet actuator and the mean near-wake flow are depicted by means of Particle Image Velocimetry. In order to compare this closed-loop strategy we first present two open-loop ones. Continuous blowing is initially used to directly influence the recirculation area and hence achieve a reduction in the drag. Approximately a drag reduction of 8% is accomplished making this approach the "optimal case" control strategy. However, because steady blowing mechanisms lead to the highest energy consumption scheme, this strategy will only serve as the first open-loop control reference. The second open-loop strategy involves three periodic forcing frequencies, St A = 0.0765, 0.135 & 0.405. The influence of these frequencies on the near-wake, and its further drag modification, will be further examined. The proposed sliding mode control (closed-loop strategy) is applied to the same Ahmed body configuration and compared to the open-loop cases. It will be designed on the basis of a simplified input-output model which was recently defined for another flow control application. Last, a second experiment is conducted so to show the disturbance rejection of the controller, corroborating the robustness and efficiency of this control approach. Its limitations and difficulties on an experimental setup are also discussed. SMC is able to reduce and maintain the drag to a desire set-point regardless external flow perturbations. Our control strategy was recently used in another context (flow reattachement on a wing) with the same robustness. These successes make guess it is applicable to multiple experimental and industrial contexts.
Published: 2020

15. Delamination Morphology Maps of Chromium Oxide Scales Formed on Cr-Based Alloys

Author: Ph. Goudeau, Mathieu Guerain, Jean-Luc Grosseau-Poussard, Unité Matériaux et Transformations - UMR 8207 (UMET), Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centrale Lille Institut (CLIL), Surface, Interfaces et MAtériaux sous Contrainte SIMAC (SIMAC), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences de l'Ingénieur pour l'Environnement - UMR 7356 (LaSIE), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), and Centrale Lille-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: Materials science, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], 0211 other engineering and technologies, Oxide, 02 engineering and technology, 01 natural sciences, Microscopic scale, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Stress (mechanics), chemistry.chemical_compound, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Residual stress, 0103 physical sciences, Stress relaxation, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], 021102 mining & metallurgy, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 010302 applied physics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Delamination, Metallurgy, Metals and Alloys, Fracture mechanics, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Condensed Matter Physics, Chromia, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Mechanics of Materials, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph]
Abstract: International audience; The delamination processes occurring in chromia scales formed on Ni-30Cr and Fe-47Cr alloys were studied. Delamination is the result of the competition between growth stresses evolution during heating, thermal stresses during cooling, and stress release phenomena, leading to high residual stress in the oxide film. Delamination in chromia has been found to occur due to type and amount of residual stresses generated at the end of heating-induced chromia growth and subsequent cooling-induced differential shrinkage. The mapping of the residual stresses in the oxide films at the microscopic scale around the delaminations allow to classify the latter into three different groups: buckles of Type 1, buckles of Type 2, and spalls. Using the stress relaxation magnitude, an assessment of the interfacial toughness of the metal/oxide systems was carried out, thanks to the buckling and crack propagation theory in the oxide. From the value obtained, microscopic observations, and the residual stress maps, a diagram describing the spalling of the buckles for chromia scales is proposed, as well as the delamination maps of Fe-47Cr/Cr2O3 and Ni-30Cr/Cr2O3 systems specifying the conditions of existence of the obtained delamination features.
Published: 2020

16. Dislocation emission and crack propagation during thin film buckling on substrate

Author: Jérôme Colin, Benjamin Bertin, Julien Durinck, Surface, Interfaces et MAtériaux sous Contrainte SIMAC (SIMAC), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers
Subjects: Materials science, Plasticity, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Nucleation, Dislocations, 02 engineering and technology, Modelling, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Condensed Matter::Materials Science, Molecular dynamics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Thin film, Buckle, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Crack, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Applied Mathematics, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Fracture mechanics, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Condensed Matter Physics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, Buckling, Mechanics of Materials, Delamination, Modeling and Simulation, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Dislocation, 0210 nano-technology, Buckling failure
Abstract: International audience; The buckling of a gold thin film deposited on a rigid substrate has been numerically investigated by means of static molecular dynamics simulations. Three different regimes of deformation have been identified depending on the values of the adhesion energy of the film on its substrate (Gamma(int)). For low adhesion energy, the buckling and gliding through dislocation emission into the interface have been observed. For intermediate values of Gamma(int), the dissociation of the interfacial dislocations into the film leads to the formation of a Lomer-Cottrell lock that stops the buckle extension, promoting thus the propagation of a crack accompanied by the emission of dislocations. It results in the formation of a twin. For large values of Gamma(int,) the kinking of the interfacial crack has been evidenced along with dislocation nucleation at its tip leading to twins again. Finally, the different evolutions of the film have been summarized in a "behavior" diagram displayed in the plane of applied strain and adhesion energy variables. (C) 2019 Elsevier Ltd. All rights reserved.
Published: 2020

17. Direct measurements of slip irreversibility in a nickel-based superalloy using high resolution digital image correlation

Author: Valéry Valle, Marie-Agathe Charpagne, Jean Charles Stinville, Patrick G. Callahan, McLean P. Echlin, Tresa M. Pollock, University of California [Santa Barbara] (UCSB), University of California, Photomécanique et analyse expérimentale en Mécanique des solides (PEM), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers
Subjects: Digital image correlation, Scanning electron microscopy digital image correlation, Materials science, Strain localization and accumulation, Polymers and Plastics, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Heaviside-digital image correlation, Nucleation, 02 engineering and technology, Slip (materials science), Plasticity, 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Polycrystalline René 88DT nickel-based superalloy, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Slip irreversibility, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 010302 applied physics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Low cycle fatigue, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Lüders band, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, High resolution digital image correlation, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Microstructure, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Electronic, Optical and Magnetic Materials, Superalloy, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Ceramics and Composites, Crystallite, 0210 nano-technology
Abstract: International audience; Fatigue crack nucleation in crystalline materials typically develops due to highly localized cyclic slip. During a fatigue cycle, reverse slip differs locally from slip in the forward direction particularly in precipitate-containing materials such as superalloys. In this paper we report the first direct measurements of irreversibility at the scale of individual slip bands by high-resolution digital image correlation (DIC) in a polycrystalline nickel-based superalloy. Quantitative measurements of the slip irreversibility are challenging for regions of material that have a size that captures the microstructure and its variability. High spatial resolution at the nanometer scale during experimental measurements is needed to observe slip localization during deformation. Moreover, large fields are also needed to obtain the material response over statistically representative populations of microstructural configurations. Recently, high resolution scanning electron microscope (SEM) digital image correlation (DIC) has been extended for quantitative analysis of discontinuities induced by slip events using the Heaviside-DIC method. This novel method provides quantitative measurements of slip localization at the specimen surface. In this paper, the Heaviside-DIC method is used to measure slip irreversibility and plastic strain accumulation in a nickel-based superalloy. The method detects bands with high levels of irreversibility early in cycling that ultimately form fatigue cracks upon further cycling. The local microstructural configurations that induce large amounts of plasticity and slip irreversibility are correlated to crack nucleation locations.
Published: 2020

18. Pose2Sim: An End-to-End Workflow for 3D Markerless Sports Kinematics-Part 2: Accuracy

Author: Mathieu Domalain, Lionel Reveret, David Pagnon, Calcul des Variations, Géométrie, Image (CVGI), Laboratoire Jean Kuntzmann (LJK), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Robotique, Biomécanique, Sport, Santé (RoBioSS), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), and ANR-20-STHP-0003,PERFANALYTICS,Analyse in situ de la performance(2020)
Subjects: musculoskeletal diseases, Kinematics, Knee Joint, Sports performa, Walking, Biochemistry, Analytical Chemistry, Running, Workflow, OpenPose, Motion, [INFO.INFO-LG]Computer Science [cs]/Machine Learning [cs.LG], [INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering, Humans, Electrical and Electronic Engineering, OpenSim, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Instrumentation, Markerless moti, Gait, markerless motion capture, sports performance analysis, kinematics, computer vision, deep learning, concurrent validity, accuracy, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], Deep learning, Atomic and Molecular Physics, and Optics, Biomechanical Phenomena, concurrent vali, Computer vision, Ankle Joint
Abstract: Two-dimensional deep-learning pose estimation algorithms can suffer from biases in joint pose localizations, which are reflected in triangulated coordinates, and then in 3D joint angle estimation. Pose2Sim, our robust markerless kinematics workflow, comes with a physically consistent OpenSim skeletal model, meant to mitigate these errors. Its accuracy was concurrently validated against a reference marker-based method. Lower-limb joint angles were estimated over three tasks (walking, running, and cycling) performed multiple times by one participant. When averaged over all joint angles, the coefficient of multiple correlation (CMC) remained above 0.9 in the sagittal plane, except for the hip in running, which suffered from a systematic 15° offset (CMC = 0.65), and for the ankle in cycling, which was partially occluded (CMC = 0.75). When averaged over all joint angles and all degrees of freedom, mean errors were 3.0°, 4.1°, and 4.0°, in walking, running, and cycling, respectively; and range of motion errors were 2.7°, 2.3°, and 4.3°, respectively. Given the magnitude of error traditionally reported in joint angles computed from a marker-based optoelectronic system, Pose2Sim is deemed accurate enough for the analysis of lower-body kinematics in walking, cycling, and running.
Published: 2022

19. In situ radiographic and ex situ tomographic investigation of pore collapse in laser shock-loaded polyurethane foam

Author: P. Pradel, T. de Rességuier, F. Malaise, M. P. Olbinado, A. Rack, J. Grenzer, D. Loison, L. Berthe, Centre d'études scientifiques et techniques d'Aquitaine (CESTA), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ingénierie des Matériaux (LIM), Centre National de la Recherche Scientifique (CNRS), French Government program 'Investissements d'Avenir' (EQUIPEX GAP)French National Research Agency (ANR) [ANR-11-EQPX-0018], ANR-11-EQPX-0018,GAP,Plate-forme d'essais et de recherche sur les nouvelles technologies de ' Groupe Aéro Propulseur ' pour l'aéronautique et le spatial(2011), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), European Synchroton Radiation Facility [Grenoble] (ESRF), Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, and HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)
Subjects: [PHYS]Physics [physics], [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], General Physics and Astronomy, Shock waves, Synchrotrons, X-ray imaging, Radiography, Tomography, Elastic waves, Hydrodynamics simulations, Polymers
Abstract: International audience; Laser-driven shock experiments were conducted at a synchrotron facility to investigate the dynamic response of polyurethane foam. These experiments were coupled to in situ x-ray imaging to radiograph foam deformations and to determine the propagation velocity of stress waves. To increase the amplitude and the duration of the pressure load generated by the laser-matter interaction, the front surface of the target was covered with a confining layer (water and BK7 glass). Preliminary calibration tests involving time-resolved velocity measurements were performed to calculate the ablation pressure on the front surface of foam samples. The calculated pressure loads were used as input data for hydrodynamic simulations, in which the foam is modeled using a homogeneous porous macroscopic model, and model predictions were compared with experimental results. A fair consistency was found for most experiments, while for the others, an overestimation of the applied pressure is suspected, likely due to a laser breakdown within the confining medium. Finally, post-shot x-ray tomography of the recovered samples showed permanent deformation of the foam, unlike what was observed under quasi-static compression, and revealed heavy damage in the vicinity of the loaded zone.
Published: 2022

20. Influence of chemistry on the steady solutions of hydrogen gaseous detonations with friction losses

Author: Fernando Veiga-López, Luiz M. Faria, Josué Melguizo-Gavilanes, Détonique (DETO ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Propagation des Ondes : Étude Mathématique et Simulation (POEMS), Inria Saclay - Ile de France, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Unité de Mathématiques Appliquées (UMA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-Centre National de la Recherche Scientifique (CNRS), and ANR-20-CE05-0011,FASTD,Accélération de la flamme et passage à la détonation dans des canaux étroits(2020)
Subjects: chemical mechanisms, Fuel Technology, General Chemical Engineering, hydrogen, detonation, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, friction, General Physics and Astronomy, Energy Engineering and Power Technology, General Chemistry
Abstract: International audience; The problem of the steady propagation of detonation waves with friction losses is revisited including detailed kinetics. The derived formulation is used to study the influence of chemical modeling on the steady solutions and reaction zone structures obtained for stoichiometric hydrogen-oxygen. Detonation velocity-friction coefficient (D − c f) curves, pressure, temperature, Mach number, thermicity and species profiles are used for that purpose. Results show that both simplified kinetic schemes considered (i.e., one-step and three-step chainbranching), fitted using standard methodologies, failed to quantitatively capture the critical c f values obtained with detailed kinetics; moreover one-step Arrhenius chemistry also exhibits qualitative differences for D/D CJ ≤ 0.55 due to an overestimation of the chemical time in this regime. An alternative fitting methodology for simplified kinetics is proposed using detailed chemistry D − c f curves as a target rather than constant volume delay times and ideal Zel'dovich-von Neumann-Döring profiles; this method is in principle more representative to study non-ideal detonation propagation. The sensitivity of the predicted critical c f value, c f,crit , to the detailed mechanisms routinely used to model hydrogen oxidation was also assessed; significant differences were found, mainly driven by the consumption/creation rate of the HO 2 radical pool at low postshock temperature.
Published: 2022

21. Highly Transparent and Conductive Indium‐Free Vanadates Crystallized at Reduced Temperature on Glass Using a 2D Transparent Nanosheet Seed Layer

Author: Aimane Cheikh, Mathieu Frégnaux, Christophe Labbé, Wilfrid Prellier, Valérie Demange, Thierry Girardeau, Philippe Marie, Julien Cardin, Bruno Berini, Ulrike Lüders, Damien Aureau, Marie Dallocchio, Arnaud Fouchet, Fabien Paumier, Simon Hurand, Yves Dumont, Maryline Guilloux-Viry, Andréia Márcia Santos de Souza David, Alexis Boileau, F. Baudouin, Laboratoire de cristallographie et sciences des matériaux (CRISMAT), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Synthèse Caractérisation Analyse de la Matière (ScanMAT), Université de Rennes (UR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Groupe d'Etude de la Matière Condensée (GEMAC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Nanomatériaux, Ions et Métamatériaux pour la Photonique (NIMPH), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut Lavoisier de Versailles (ILV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale de la Recherche. Grant Number: ANR-17-CE08-0012 FEDER. Grant Number: 17P04263/17P04260, ANR-17-CE08-0012,Polynash,Substrats bas couts polycristallins et Nanofeuillets de germination(2017), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)
Subjects: Spectroscopic ellipsometry, Materials science, Oxide, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, 01 natural sciences, Biomaterials, chemistry.chemical_compound, Nanosheets, 0103 physical sciences, Electrochemistry, Vanadate, Electrical conductor, Nanosheet, 010302 applied physics, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Correlated metals, Reduced properties, chemistry, Transparent conducting oxide, 0210 nano-technology, Layer (electronics), Indium, Perovskite thin films
Abstract: International audience; Indium-tin-oxide (ITO) is a widely employed transparent conducting oxide (TCO), but the indium scarcity and price encourage developing some alternatives. The correlated metals CaVO3 and SrVO3 have been recently identified as new TCOs with functional properties being comparable to ITO. However, their technological potential is limited by the critical requirement of a perovskite structure of the film, impossible to achieve via direct growth on substrates commonly used for applications. In this article, the authors tackle this limitation by demonstrating the crystalline growth of vanadate TCOs on glass at temperatures below 600 °C, with the help of 2D nanosheets as transparent seed layers. The functional properties do not suffer from the textured structure of the films, as confirmed by an in-depth spectroscopic ellipsometry study, allowing for an industrially viable approach to integrate vanadate TCOs on virtually any surface and to exploit their promising performances as a new generation TCO
Published: 2022

22. Simultaneous Optical and Electrical Characterization of GaN Nanowire Arrays by Means of Vis-IR Spectroscopic Ellipsometry

Author: S. Hurand, F. Paumier, Bertrand Lacroix, Victor J. Gómez, Antonio J. Santos, Rafael García, Francisco M. Morales, Thierry Girardeau, Diana L. Huffaker, Eduardo Blanco, Fraunhofer AICOS [Porto], Instituto de Ciencia de Materiales de Sevilla (ICMSE), Universidad de Sevilla-Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Universidad Simon Bolivar (USB), Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Institut Pprime (PPRIME), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7), Université de Montréal [Montréal], Fraunhofer Center for Assistive Information and Communication Solutions [Porto] (Fraunhofer AICOS), Fraunhofer (Fraunhofer-Gesellschaft), Universidad de Sevilla-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Montréal (UdeM), Universidad de Sevilla / University of Sevilla-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Astrophysique Interprétation Modélisation (AIM (UMR7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Diffraction, Materials science, Silicon, Infrared, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Nanowire, Physics::Optics, chemistry.chemical_element, 02 engineering and technology, 010402 general chemistry, Epitaxy, 01 natural sciences, Nitrides, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Condensed Matter::Materials Science, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Hall effect, Ellipsometry, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Physical and Theoretical Chemistry, Oscillation Mobility, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Nanowires, business.industry, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 0104 chemical sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Characterization (materials science), [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, General Energy, chemistry, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Optoelectronics, 0210 nano-technology, business, Porosity
Abstract: International audience; We report an original and straightforward method for both optical and electrical characterization of vertical GaN nanowire arrays epitaxially grown on silicon through visible-infrared spectroscopic ellipsometry methods. For the initial purpose of adding new inputs to the ellipsometry model, focused ion-beam tomography experiments were conducted to extract porosity/depth profiles of these systems. To reproduce the optical free-carrier behavior in the infrared, the ellipsometric data acquired were fitted to an anisotropic Bruggeman model including Tauc-Lorentz and Drude oscillators, which enabled the determination of carrier density and in-grain mobility. The nice agreement of these results with those obtained by combining Hall effect measurements, X-ray diffraction, and transmission electron microscopy studies supported the validity of the proposed method, opening new horizons in the characterization of nanowire-based semiconducting layers.
Published: 2019

23. Lentil sprouts: a nutraceutical alternative for the elaboration of bread

Author: C. Valderrama-Bravo, Marcos Soto Hernández, A. Dominguez-Pacheco, Alfredo Cruz-Orea, Claudia Hernández-Aguilar, Mariana Palma Tenango, Jose Ordonez-Miranda, Thermique aux Nano échelles et Rayonnement (TNR ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: 030309 nutrition & dietetics, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Population, bread, Wheat flour, wheat flour, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [SPI]Engineering Sciences [physics], 03 medical and health sciences, chemistry.chemical_compound, lentil sprout, 0404 agricultural biotechnology, Nutraceutical, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Food science, Phenols, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], education, Isorhamnetin, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 2. Zero hunger, 0303 health sciences, education.field_of_study, secondary metabolites, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, digestive, oral, and skin physiology, fungi, food and beverages, [CHIM.MATE]Chemical Sciences/Material chemistry, 04 agricultural and veterinary sciences, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 040401 food science, Falling Number, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, Germination, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Original Article, Quercetin, Food Science
Abstract: International audience; The pro-health action of germinated lentils could be useful to be added with wheat flour in the production of box bread. In this work, we spectroscopically evaluate the germinated and non-germinated lentils, and use them at the concentrations of 5 and 10% for the production of box bread. The chemical and physical tests of the bread and its determination of phenolic acids and flavonoids (by HPLC) were also performed. As well as the evaluation of the quality of flour and dough used to produce the bread and the acceptance of the germinated lentil bread with a population of 20 people with diabetes or with diabetic relatives It is shown that: (1) The amplitude of photoacoustic signal obtained by photoacoustic spectroscopy is modified as a function of the percentage of germinated lentil (GL) flour (0, 5 or 10%) add to the bread; being higher the photoacoustic amplitude to higher concentration of GL in the absorption band of 300–425 nm, which is related to higher content of phenols and flavonoids. (2) The contents of phenolic acids (Sinapinic, β- resorcylic, Chlorogenic and Ferulic) and flavonoids (Quercetin and Isorhamnetin) tended to increase in the germinated lentil bread with 10% concentration of germinated lentil flour with respect to the control bread (0% GL). (3) The addition of germinated lentils flour to 5 and 10% into wheat flour to produce bread with higher hardness and less cohesiveness than bread based on wheat flour only. The Falling number indicate that there is no significant difference between the control sample and the 5% GL flour, while in the 10% GL flour there was a reduction of 21 s, with respect to the control. The effect of the germinated lentil flour percentage on the pasting properties of the flours was significant between the control and 10% GL flour. In general, the quality of the dough and flour are modified due to the addition of germinates lentils, and this affectation increases with the increase in the concentration of GL. (4) The bread added with germinated lentil has sensory acceptance with a group of people with diabetes and/or diabetic relatives in their attributes in general. The obtained results thus support the production of wheat bread with mixed germinated lentils flour, as a nutraceutical option for human consumption.
Published: 2019

24. Hot surface ignition dynamics in premixed hydrogen–air near the lean flammability limit

Author: L.R. Boeck, J. Melguizo-Gavilanes, Joseph E. Shepherd, Graduate Aerospace Laboratories of the California Institute of Technology (GALCIT), California Institute of Technology (CALTECH), Détonique (DETO ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: Hot surface, Hydrogen, General Chemical Engineering, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], General Physics and Astronomy, Numerical simulation, 02 engineering and technology, Combustion, 7. Clean energy, 01 natural sciences, law.invention, Physics::Fluid Dynamics, law, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Physics::Chemical Physics, Pyrometer, [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 010304 chemical physics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [CHIM.MATE]Chemical Sciences/Material chemistry, Mechanics, Ignition, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Boundary layer, Fuel Technology, Materials science, Energy Engineering and Power Technology, chemistry.chemical_element, Schlieren imaging, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 020401 chemical engineering, Physics::Plasma Physics, 0103 physical sciences, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], 0204 chemical engineering, Flammability limit, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.NRJ]Engineering Sciences [physics]/Electric power, General Chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Ignition system, [CHIM.POLY]Chemical Sciences/Polymers, chemistry, 13. Climate action, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Glow plug, Experiments
Abstract: International audience; The dynamics of ignition of premixed hydrogen–air from a hot glow plug were investigated in a combined experimental and numerical study. Surface temperatures during heating and at ignition were obtained from 2-color pyrometry, gas temperatures were measured by high-speed Mach–Zehnder interferometry, and far-field effects were captured by high-speed schlieren imaging. Numerical simulations considered detailed chemical kinetics and differential diffusion effects. In addition to the known cyclic (puffing) combustion phenomenon, singular ignition events (single puff) were observed near the lean flammability limit. Detailed analysis of the results of our numerical simulations reveal the existence of multiple combustion transients within the thermal boundary layer following the initial ignition event and, at late times, sustained chemical reaction within a thermal plume above the glow plug. The results have significant implications for ignition from hot surfaces within near-flammability limit mixtures, at the edge of plumes resulting from accidental release of hydrogen, or within the containments of nuclear power plants during severe accidents.
Published: 2019

25. A Novel Multi-Dimensional Clinical Response Index Dedicated to Improving Global Assessment of Pain in Patients with Persistent Spinal Pain Syndrome after Spinal Surgery, Based on a Real-Life Prospective Multicentric Study (PREDIBACK) and Machine Learning Techniques

Author: Maxime Billot, Maarten Moens, Philippe Page, Amine Ounajim, Chantal Wood, Laure Poupin, Yousri Slaoui, Brigitte Roy-Moreau, Pierre-Yves Louis, Philippe Rigoard, Romain David, M. Roulaud, Nihel Adjali, Mathilde Many, Nelly Grimaud, Lisa Goudman, Delphine Rannou, Sandrine Baron, Raphael Rigoard, Géraldine Brumauld de Montgazon, Bénédicte Bouche, Elodie Charrier, Kevin Nivole, Nicolas Naiditch, Bertille Lorgeoux, Supporting clinical sciences, Neurosurgery, Pain in Motion, Neuroprotection & Neuromodulation, Radiology, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), prismatics (PRISMATICS), Centre hospitalier universitaire de Poitiers (CHU Poitiers), Department of Spine Surgery & Neuromodulation, Poitiers University Hospital, 86021 Poitiers, France, Laboratoire de Mathématiques et Applications (LMA-Poitiers), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Department of Neurosurgery, Universitair Ziekenhuis Brussel, 1090 Brussels, Belgium, STUMULUS Research Group, Vrije Universiteit Brussel, 1090 Brussels, Belgium, Institut de Mathématiques de Bourgogne [Dijon] (IMB), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB), Procédés Alimentaires et Microbiologiques [Dijon] (PAM), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Dynamiques européennes (DynamE), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Pain Evaluation and Treatment Centre, Poitiers University Hospital, 86021 Poitiers, France, Pain Evaluation and Treatment Centre, La Rochelle Hospital, 17000 La Rochelle, France, Pain Evaluation and Treatment Centre, Nord Deux-Sèvres Hospital, 79000 Niort, France, Pain Evaluation and Treatment Centre, Centre Clinical Elsan, 16800 Soyaux, France, Physical and Rehabilitation Medicine Unit, Poitiers University Hospital, University of Poitiers, 86021 Poitiers, France, Service des Technologies de l’Information et de la Communication (STIC), CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), STIMULUS research group, Vrije Universiteit Brussel, 1090 Brussels, Belgium, MedtronicERP NM-3351Poitiers University Hospital, France, Photomécanique et analyse expérimentale en Mécanique des solides (PEM), Département Génie Mécanique et Systèmes Complexes (GMSC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Bourgogne (UB)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS), and Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement-Université Bourgogne Franche-Comté [COMUE] (UBFC)
Subjects: Index (economics), pain mapping, functional capacity, 030204 cardiovascular system & hematology, computer.software_genre, Machine Learning, surgery, 0302 clinical medicine, Quality of life, psychological distress, Pain assessment, [MATH.MATH-ST]Mathematics [math]/Statistics [math.ST], 030212 general & internal medicine, Quality Of Life, media_common, pain intensity, [STAT.AP]Statistics [stat]/Applications [stat.AP], anxiety and depression, 05 social sciences, Chronic pain, General Medicine, Spinal pain, 3. Good health, Medicine, PSPS, composite score, chronic pain, medicine.medical_specialty, Composite score, media_common.quotation_subject, pain surface, Machine learning, Article, 03 medical and health sciences, general_medical_research, Perception, 0502 economics and business, medicine, failed back surgery syndrome (FBSS), In patient, [SDV.EE.SANT]Life Sciences [q-bio]/Ecology, environment/Health, business.industry, medicine.disease, Spinal surgery, Anesthesiology and Pain Medicine, Multi dimensional, Physical therapy, 050211 marketing, Observational study, Pairwise comparison, [SDV.SPEE]Life Sciences [q-bio]/Santé publique et épidémiologie, Artificial intelligence, failed back surgery syndrome, business, computer, 030217 neurology & neurosurgery
Abstract: The multidimensionality of chronic pain forces us to look beyond isolated assessment such as pain intensity, which does not consider multiple key parameters, particularly in post-operative Persistent Spinal Pain Syndrome (PSPS-T2) patients. Our ambition was to produce a novel Multi-dimensional Clinical Response Index (MCRI), including not only pain intensity but also functional capacity, anxiety-depression, quality of life and quantitative pain mapping, the objective being to achieve instantaneous assessment using machine learning techniques. Two hundred PSPS-T2 patients were enrolled in the real-life observational prospective PREDIBACK study with 12-month follow-up and received various treatments. From a multitude of questionnaires/scores, specific items were combined, as exploratory factor analyses helped to create a single composite MCRI, using pairwise correlations between measurements, it appeared to more accurately represent all pain dimensions than any previous classical score. It represented the best compromise among all existing indexes, showing the highest sensitivity/specificity related to Patient Global Impression of Change (PGIC). Novel composite indexes could help to refine pain assessment by informing the physician’s perception of patient condition on the basis of objective and holistic metrics, and also by providing new insights regarding therapy efficacy/patient outcome assessments, before ultimately being adapted to other pathologies.
Published: 2021

26. Experimental study of a natural convection flow in a cubic enclosure with a partially heated inner block

Author: Alexandre Weppe, Florian Moreau, Didier Saury, Ecole Nationale Supérieure de Mécanique et d'Aérotechnique [Poitiers] (ISAE-ENSMA), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Convection, Optimisation, Systèmes Thermiques (COST ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), CPER-FEDER 2014-2020 program, and ANR-17-CE06-0005,MONACO_2025,Modélisation de la convection naturelle : un défi pour l'ambition Tout Numérique 2025(2017)
Subjects: Physics::Fluid Dynamics, History, 020303 mechanical engineering & transports, 0203 mechanical engineering, 0103 physical sciences, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], 02 engineering and technology, 01 natural sciences, 010305 fluids & plasmas, Computer Science Applications, Education
Abstract: In many industrial contexts, buoyancy driven flows are the only cooling strategy in case of breakdown of the forced convection cooling system. In order to study those flows in a simplified configuration, a buoyancy-driven flow is generated inside a cubic enclosure by a partially heated block (Ra = 1.4 × 109). The flow is studied experimentally in the vertical median plane, in the part of the enclosure where the flow is generated i.e. close to the heated side of the block. Velocity fields, mean profiles and RMS statistics are analyzed. The results show the presence of boundary layer flows with a central zone nearly at rest and stratified. RMS velocities are intensified with elevation.
Published: 2021

27. Experimental investigation of an electrostatic adhesion device used for metal/polymer granular mixture sorting

Author: Amar Tilmatine, Ayyoub Zouaghi, Hamza Louati, Rabah Ouiddir, Noureddine Zouzou, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Génie Electrique d'Oran (LGEO), Applications of Plasma, Electrostatics and Electromagnetic Compatibility (APELEC), Université Djilali Liabès [Sidi-Bel-Abbès], Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Ampère, Département Energie Electrique (EE), Ampère (AMPERE), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-École Centrale de Lyon (ECL), and Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: chemistry.chemical_classification, Materials science, General Chemical Engineering, Sorting, 02 engineering and technology, Dielectric, Polymer, Adhesion, 021001 nanoscience & nanotechnology, Granular material, Metal, [SPI]Engineering Sciences [physics], 020401 chemical engineering, chemistry, visual_art, Electrode, visual_art.visual_art_medium, 0204 chemical engineering, Composite material, 0210 nano-technology, Actuator, ComputingMilieux_MISCELLANEOUS
Abstract: Electrostatic adhesion (EA) technique have been used recently for the electrostatic sorting of metal/polymer granular material mixture. The action seat on the materials is an EA actuator composed of an interposed electrodes network covered by a dielectric barrier and powered by polyphase voltages. The sorting principle consists of attaching the metal particles by EA, and of moving the polymer particles larger than 500 μm, mainly by gravity and vibration. The purpose of this paper is to optimize the EA mechanism for electrostatic sorting. The first part consists of evaluating the behavior of materials (Cu, PE, and PVC) on the EA actuator surface using a 180°-rotating system. The results showed that the metal attaches to the actuator surface while the polymer does not; they also indicate the optimal factors contributing to the adhesion process. In the second part related to sorting application, the granular materials behavior and the influencing factors are explored in an inclined vibrating system to process a Cu/PVC mixture. For an inclination of 10°, Cu recovery on the actuator exceeds 98% with a purity of about 99%.
Published: 2021

28. Experimental study of Natural convection flow in a cubic enclosure with a partially heated inner block

Author: Weppe, Alexandre, Moreau, Florian, Saury, Didier, Ecole Nationale Supérieure de Mécanique et d'Aérotechnique [Poitiers] (ISAE-ENSMA), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Convection, Optimisation, Systèmes Thermiques (COST ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE06-0005,MONACO_2025,Modélisation de la convection naturelle : un défi pour l'ambition Tout Numérique 2025(2017), Saury, Didier, and Modélisation de la convection naturelle : un défi pour l'ambition Tout Numérique 2025 - - MONACO_20252017 - ANR-17-CE06-0005 - AAPG2017 - VALID
Subjects: Physics::Fluid Dynamics, [PHYS.MECA.THER] Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph], [SPI.MECA.THER] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph]
Abstract: International audience; In many industrial contexts, buoyancy driven flows are the only cooling strategy in case of breakdown of the forced convection cooling system. In order to study those flows in a simplified configuration, a buoyancy-driven flow is generated inside a cubic enclosure by a partially heated block (Ra = 1.4E9). The flow is studied experimentally in the vertical median plane, in the part of the enclosure where the flow is generated i.e. close to the heated side of the block. Velocity elds, mean proles and RMS statistics are analyzed. The results show the presence of boundary layer ows with a central zone nearly at rest and stratied. RMS velocities are intensitied with elevation.
Published: 2021

29. The Community Inversion Framework v1.0: A unified system for atmospheric inversion studies

Author: Rona Thompson, Wouter Peters, Jean-Matthieu Haussaire, Ingrid T. Luijkx, Joël Thanwerdas, Grégoire Broquet, Werner L. Kutsch, Peter Bergamaschi, Richard Engelen, Jacob C. A. van Peet, Audrey Fortems-Cheiney, Christoph Gerbig, Espen Sollum, Philippe Peylin, Christian Rödenbeck, Yuanhong Zhao, Isabelle Pison, Sanne Houweling, Marko Scholze, Adrien Berchet, Elise Potier, Ute Karstens, Paul I. Palmer, Dominik Brunner, Christine Groot Zwaaftink, Aki Tsuruta, Guillaume Monteil, Marielle Saunois, Frédéric Chevallier, Tuula Aalto, Antoine Berchet, Stephan Henne, Earth Sciences, Earth and Climate, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), The Community Inversion Framework is currently funded by the project (http://verify.lsce.ipsl.fr, last access:23 August 2021), which received funding from the EuropeanUnion’s Horizon 2020 research and innovation programme undergrant agreement no. 776810, European Project: 776810,H2020,H2020-SC5-2017-OneStageB,VERIFY(2018), Isotope Research, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Hydrodynamique et Ecoulements Environnementaux (HydEE), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Norwegian Institute for Air Research (NILU), Finnish Meteorological Institute (FMI), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, European Commission - Joint Research Centre [Ispra] (JRC), Swiss Federal Laboratories for Materials Science and Technology [Dübendorf] (EMPA), European Centre for Medium-Range Weather Forecasts (ECMWF), Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Vrije Universiteit Amsterdam [Amsterdam] (VU), Department of Physical Geography and Ecosystem Science [Lund], Lund University [Lund], Integrated Carbon Observation System (ICOS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Meteorology and Air Quality Group, Wageningen University and Research [Wageningen] (WUR), School of Geosciences [Edinburgh], and University of Edinburgh
Subjects: 010504 meteorology & atmospheric sciences, Computer science, [SDE.MCG]Environmental Sciences/Global Changes, 010501 environmental sciences, Luchtkwaliteit, 01 natural sciences, Air Quality, Data assimilation, SDG 13 - Climate Action, Life Science, Leverage (statistics), [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Protocol (object-oriented programming), 0105 earth and related environmental sciences, computer.programming_language, Flexibility (engineering), [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, QE1-996.5, WIMEK, Bayesian optimization, Inversion (meteorology), Geology, Python (programming language), 13. Climate action, Greenhouse gas, Systems engineering, computer
Abstract: Atmospheric inversion approaches are expected to play a critical role in future observation-based monitoring systems for surface fluxes of greenhouse gases (GHGs), pollutants and other trace gases. In the past decade, the research community has developed various inversion software, mainly using variational or ensemble Bayesian optimization methods, with various assumptions on uncertainty structures and prior information and with various atmospheric chemistry–transport models. Each of them can assimilate some or all of the available observation streams for its domain area of interest: flask samples, in situ measurements or satellite observations. Although referenced in peer-reviewed publications and usually accessible across the research community, most systems are not at the level of transparency, flexibility and accessibility needed to provide the scientific community and policy makers with a comprehensive and robust view of the uncertainties associated with the inverse estimation of GHG and reactive species fluxes. Furthermore, their development, usually carried out by individual research institutes, may in the future not keep pace with the increasing scientific needs and technical possibilities. We present here the Community Inversion Framework (CIF) to help rationalize development efforts and leverage the strengths of individual inversion systems into a comprehensive framework. The CIF is primarily a programming protocol to allow various inversion bricks to be exchanged among researchers. In practice, the ensemble of bricks makes a flexible, transparent and open-source Python-based tool to estimate the fluxes of various GHGs and reactive species both at the global and regional scales. It will allow for running different atmospheric transport models, different observation streams and different data assimilation approaches. This adaptability will allow for a comprehensive assessment of uncertainty in a fully consistent framework. We present here the main structure and functionalities of the system, and we demonstrate how it operates in a simple academic case.
Published: 2021

30. An indicator to characterize hydrological alteration due to hydropeaking

Author: Dominique Courret, Michel Larinier, Philippe Baran, Centre National de la Recherche Scientifique - CNRS (FRANCE), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique - ENSMA (FRANCE), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), Université Toulouse III - Paul Sabatier - UT3 (FRANCE), Université de Poitiers (FRANCE), Office français de la biodiversité - OFB (FRANCE), Etudes et COnseils en Gestion de l'Environnement Aquatique - ECOGEA (FRANCE), Institut Recherche et Ingénierie en Matériaux, Mécanique et Energétique - Pprime (Chasseneuil-du-Poitou, France), Institut de mécanique des fluides de Toulouse (IMFT), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées, Office français de la biodiversité (OFB), Mécanique des Interfaces Lubrifiées (TriboLub), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Etudes et Conseils en Gestion de l'Environnement Aquatique - ECOGEA (FRANCE), and ISAE-ENSMA Ecole Nationale Supérieure de Mécanique et d'Aérotechnique (FRANCE)
Subjects: Hydrology, 010504 meteorology & atmospheric sciences, Hydrological alteration, Mécanique des fluides, Flow (psychology), 0207 environmental engineering, 02 engineering and technology, [SDV.BID]Life Sciences [q-bio]/Biodiversity, 01 natural sciences, 6. Clean water, Rate of change, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Indicator, Abundance (ecology), Hydropeaking, Range (statistics), Stream flow, Environmental science, %22">Fish , Biodiversité, 020701 environmental engineering, 0105 earth and related environmental sciences
Abstract: International audience; Hydropeaking by hydroelectric facilities generates sudden changes in river flows and can affect the composition, abundance and structure of fish and invertebrate populations over long distances. To assess the level of hydrological alteration, as a factor of risk of biological impacts, a synthetic indicator was developed. Based on the analysis of 97 hydrometric stations and 1 575 years of unaltered flow data, rates of change in flow were calculated. Formulas representing the fastest natural variations, depending on the mean stream flow, the type of variation (increase or decrease) and the range of variation were established. Based on the analysis of 80 hydrometric stations and 491 years of flow data affected by hydropeaking, a method was developed to identify hydropeaks, essentially defined as variations with a rate of change greater than the maximum natural value computed using the formulas. A synthetic indicator differentiating five levels of hydrological alteration was developed using linear discriminant analysis based on five parameters characterizing hydropeaking regimes. Examples show that this indicator is sensitive to changes in the management of hydroelectric facilities and provides information on the spatial and temporal evolutions in hydropeaking regimes, including the progressive attenuation during downstream propagation.
Published: 2021

31. Multiscale modeling of the elasto-plastic behavior of architectured and nanostructured Cu-Nb composite wires and comparison with neutron diffraction experiments

Author: Olivier Castelnau, Samuel Forest, P.O. Renault, Vincent Klosek, J.-R. Medy, Ludovic Thilly, Tang Gu, Eveline Herve-Luanco, Henry Proudhon, F. Lecouturier–dupouy, Patrick Villechaise, Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Procédés et Ingénierie en Mécanique et Matériaux (PIMM), Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire Léon Brillouin (LLB - UMR 12), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay, HESAM Université (HESAM), Laboratoire d'Ingénierie des Systèmes de Versailles (LISV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G ), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-PSL Research University (PSL)-MINES ParisTech - École nationale supérieure des mines de Paris, Procédés et Ingénierie en Mécanique et Matériaux [Paris] (PIMM), Arts et Métiers ParisTech, HESAM Université (HESAM)-HESAM Université (HESAM)-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA, Association EURATOM-CEA (CEA/DSM/DRFC), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA), Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, Université Grenoble Alpes (UGA), Physique des Défauts et de la Plasticité PDP (PDP), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Centre des Matériaux (CDM), Mines Paris - PSL (École nationale supérieure des mines de Paris), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Matériaux [Sciences de l'ingénieur], Materials science, Neutron diffraction, Composite number, Niobium, chemistry.chemical_element, 02 engineering and technology, 01 natural sciences, [SPI.MAT]Engineering Sciences [physics]/Materials, [SPI]Engineering Sciences [physics], Polycrystalline material, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], 0103 physical sciences, Ultimate tensile strength, Elasto-plasticity, Multiscale modeling, General Materials Science, Composite material, 010302 applied physics, Homogenization, Mechanical Engineering, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], 021001 nanoscience & nanotechnology, Microstructure, Finite element method, chemistry, Mechanics of Materials, Severe plastic deformation, Copper niobium wire, 0210 nano-technology
Abstract: International audience; Nanostructured and architectured copper niobium composite wires are excellent candidates for the generation of intense pulsed magnetic fields (∼100T) as they combine both high strength and high electrical conductivity. Multi-scaled Cu-Nb wires are fabricated by accumulative drawing and bundling (a severe plastic deformation technique), leading to a multiscale, architectured, and nanostructured microstructure exhibiting a strong fiber crystallographic texture and elongated grain shape along the wire axis. This paper presents a comprehensive study of the effective elasto-plastic behavior of this composite material by using two different approaches to model the microstructural features: full-field finite elements and mean-field modeling. As the material exhibits several characteristic scales, an original hierarchical strategy is proposed based on iterative scale transition steps from the nanometric grain scale to the millimetric macro-scale. The best modeling strategy is selected to estimate reliably the effective elasto-plastic behavior of Cu-Nb wires with minimum computational time. Finally, for the first time, the models are confronted to tensile tests and in-situ neutron diffraction experimental data with a good agreement.
Published: 2019

32. In situ synchrotron ultrasonic fatigue testing device for 3D characterisation of internal crack initiation and growth

Author: Nicolas Saintier, Mohamed El May, Arnaud Junet, Andrew King, Anne Bonnin, Yves Gaillard, Nicolas Ranc, Thierry Palin-Luc, Jean-Yves Buffiere, Yves Nadot, Alexandre Messager, Unité de recherche Maladies Métaboliques et Micronutriments (U3M), Institut National de la Recherche Agronomique (INRA), Institut de Mécanique et d'Ingénierie de Bordeaux (I2M), Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Laboratoire de Mécanique des Systèmes et des Procédés (LMSP), Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), Systèmes de Référence Temps Espace (SYRTE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Lyon-Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, École Nationale Supérieure d'Arts et Métiers (ENSAM), HESAM Université (HESAM)-HESAM Université (HESAM)-Institut Polytechnique de Bordeaux-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Bordeaux (UB), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Institut Pprime (PPRIME), and Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA
Subjects: Ultrasonic fatigue testing, In situ, Matériaux [Sciences de l'ingénieur], Cracks, Materials science, education, 0211 other engineering and technologies, 02 engineering and technology, Fatigue testing, [SPI.MAT]Engineering Sciences [physics]/Materials, law.invention, 0203 mechanical engineering, law, Ability testing, General Materials Science, Composite material, Plastic deformation, Tomography, health care economics and organizations, Ultrasonic testing, 021101 geological & geomatics engineering, In-situ synchrotrons, Short fatigue cracks, Synchrotron radiation, Initiation and propagation, Crack propagation, Mechanical Engineering, Casting defect, Fracture mechanics, Aluminum alloys, Synchrotron, Very high cycle fatigue, 020303 mechanical engineering & transports, Mechanics of Materials, Casting (metalworking), Crack initiation, Internal shorts, aluminum alloy - fatigue test - internal short crack growth - synchrotron radiation - X-ray tomography, X-ray tomography, Fatigue of materials, Synchrotrons, Ultrasonic fatigue
Abstract: cited By 0; International audience; This work presents a new ultrasonic fatigue testing device for studying the initiation and propagation mechanisms of internal microstructurally short fatigue cracks using in situ synchrotron tomography. Its principle is described as well as the method used for automatically detecting crack initiation and its subsequent growth. To promote internal crack initiation, specimens containing internal casting defects were tested between the high cycle and very high cycle fatigue regimes (107-109 cycles). Preliminary results show the ability of this new device to initiate an internal microstructurally short crack in a reasonable testing time and monitor its growth. © 2019 Wiley Publishing Ltd.
Published: 2019

33. The Thermal Unbalance Effect Induced by a Journal Bearing in Rigid and Flexible Rotors: Experimental Analysis

Author: Mohamed-Amine Hassini, Thibaud Plantegenet, Mihai Arghir, Pascal Jolly, Mécanique des Interfaces Lubrifiées (TriboLub), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers
Subjects: Materials science, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], 02 engineering and technology, [SPI.AUTO]Engineering Sciences [physics]/Automatic, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, Journal bearing, Thermal, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Experimental analysis, business.industry, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, Structural engineering, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Morton effect, Rotordynamic, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Surfaces, Coatings and Films, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, Mechanics of Materials, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Ball (bearing), 0210 nano-technology, business
Abstract: International audience; The present work presents the experimental analyses of a rigid (short) and a flexible (long) rotor subject to thermal unbalance effects. The rotors are supported by a ball bearing and by a cylindrical journal bearing. The differential heating generated in the journal bearing is responsible for the thermal unbalance. The results obtained with the short rotor at 7 krpm showed an increase in the synchronous amplitudes but slight phase changes before stabilization. The pronounced hysteresis of the synchronous amplitudes obtained during coast-down proved that the amplitude increase is due to the thermal unbalance. The results obtained for the long rotor at 6.6 krpm showed the same stabilized response when start-up was performed in 180 s. However, an instability leading to journal bearing contact was triggered when the start-up time was decreased to 80 s. The presented experimental results are the synchronous amplitudes and phases, the mean temperatures, and the maximum temperature differences of the journal and of the bearing and the phase lags between the high spot and the hot spot.
Published: 2019

34. Two-Dimensional Phonon Polariton Heat Transport

Author: F. Cervantes-Alvarez, Tomohide Yabuki, Alejandro Vega-Flick, Koji Miyazaki, Jose Ordonez-Miranda, Sebastian Volz, Laurent Tranchant, Juan Jose Alvarado-Gil, Satoki Hamamura, Laboratoire d'Énergétique Moléculaire et Macroscopique, Combustion (EM2C), Université Paris Saclay (COmUE)-Centre National de la Recherche Scientifique (CNRS)-CentraleSupélec, Thermique aux Nano échelles et Rayonnement (TNR ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), and Centro de Investigacion y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV)
Subjects: Materials science, Phonon, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Bioengineering, 02 engineering and technology, 7. Clean energy, Electromagnetic radiation, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Nanomaterials, Thermal conductivity, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 3ω method, Polariton, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Thin film, In-plane thermal conductivity, Surface electromagnetic waves, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Condensed matter physics, business.industry, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Transient grating technique, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Surface phonon, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Condensed Matter Physics, Silica thin film, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], 0210 nano-technology, business, Thermal energy
Abstract: International audience; As is well-known, the phonon and electron thermal conductivity of a thin film generally decreases as its thickness scales down to nanoscales due to size effects, which have dramatic engineering effects, such as overheating, low reliability, and reduced lifetime of processors and other electronic components. However, given that thinner films have higher surface-to-volume ratios, the predominant surface effects in these nanomaterials enable the transport of thermal energy not only inside their volumes but also along their interfaces. In polar nanofilms, this interfacial transport is driven by surface phonon polaritons, which are electromagnetic waves generated at mid-infrared frequencies mainly by the phonon–photon coupling along their surfaces. Theory predicts that these polaritons can enhance the in-plane thermal conductivity of suspended silica films to values higher than the corresponding bulk one, as their thicknesses decrease through values smaller than 200 nm. In this work, we experimentally demonstrate this thermal conductivity enhancement. The results show that the in-plane thermal conductivity of a 20 nm thick silica film at room temperature is nearly twice its lattice vibration counterpart. Additional thermal diffusivity measurements reveal that the diffusivity of a silica film also increases as its thickness decreases, such that the ratio of thermal conductivity/thermal diffusivity (volumetric heat capacity) remains nearly independent of the film thickness. The experimental results obtained here will enable one to build on recent interesting theoretical predictions, highlight the existence of a new heat channel at the nanoscale, and provide a new avenue to engineer thermally conductive nanomaterials for efficient thermal management.
Published: 2019

35. On the role of bulk viscosity in compressible reactive shear layer developments

Author: Pedro José Martínez Ferrer, Vincent Giovangigli, Arnaud Mura, Radouan Boukharfane, Barcelona Supercomputing Center – Centro Nacional de Supercomputación - BSC-CNS (SPAIN), Centre National de la Recherche Scientifique - CNRS (FRANCE), ISAE-ENSMA Ecole Nationale Supérieure de Mécanique et d'Aérotechnique (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), Université de Poitiers (FRANCE), Mines ParisTech (FRANCE), PSL Research University (FRANCE), Centre de Mathématiques Appliquées - CMAP (Palaiseau, France), Structures de flammes et Combustion (CT ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC - CNS), Centre de Mathématiques Appliquées - Ecole Polytechnique (CMAP), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Mécanique et d'Aérotechnique - ENSMA (FRANCE), Centre de Mathématiques Appliquées (CMAP), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Work (thermodynamics), Mécanique des fluides, Direct numerical simulation, General Physics and Astronomy, 02 engineering and technology, Reynolds stress, Enstrophy, 01 natural sciences, 7. Clean energy, Molecular Transport, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, Physics::Fluid Dynamics, [SPI]Engineering Sciences [physics], 0203 mechanical engineering, 0103 physical sciences, ComputingMilieux_MISCELLANEOUS, Mathematical Physics, Physics, Direct Numerical Simulation, Turbulence, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Volume viscosity, Mechanics, Shear Layer, 020303 mechanical engineering & transports, Turbulence kinetic energy, Oblique shock, Bulk Viscosity
Abstract: Despite 150 years of research after the reference work of Stokes, it should be acknowledged that some confusion still remains in the literature regarding the importance of bulk viscosity effects in flows of both academic and practical interests. On the one hand, it can be readily shown that the neglection of bulk viscosity (i.e., κ = 0 ) is strictly exact for mono-atomic gases. The corresponding bulk viscosity effects are also unlikely to alter the flowfield dynamics provided that the ratio of the shear viscosity μ to the bulk viscosity κ remains sufficiently large. On the other hand, for polyatomic gases, the scattered available experimental and numerical data show that it is certainly not zero and actually often far from negligible. Therefore, since the ratio κ ∕ μ can display significant variations and may reach very large values (it can exceed thirty for dihydrogen), it remains unclear to what extent the neglection of κ holds. The purpose of the present study is thus to analyze the mechanisms through which bulk viscosity and associated processes may alter a canonical turbulent flow. In this context, we perform direct numerical simulations (DNS) of spatially-developing compressible non-reactive and reactive hydrogen–air shear layers interacting with an oblique shock wave. The corresponding flowfield is of special interest for various reactive high-speed flow applications, e.g., scramjets. The corresponding computations either neglect the influence of bulk viscosity ( κ = 0 ) or take it into consideration by evaluating its value using the EGlib library. The qualitative inspection of the results obtained for two-dimensional cases in either the presence or the absence of bulk viscosity effects shows that the local and instantaneous structure of the mixing layer may be deeply altered when taking bulk viscosity into account. This contrasts with some mean statistical quantities, e.g., the vorticity thickness growth rate, which do not exhibit any significant sensitivity to the bulk viscosity. Enstrophy, Reynolds stress components, and turbulent kinetic energy (TKE) budgets are then evaluated from three-dimensional reactive simulations. Slight modifications are put into evidence on the energy transfer and dissipation contributions. From the obtained results, one may expect that refined large-eddy simulations (LES) may be rather sensitive to the consideration of bulk viscosity, while Reynolds-averaged Navier–Stokes (RANS) simulations, which are based on statistical averages, are not.
Published: 2019

36. Anisotropy of the triboelectric effects in polymeric slabs

Author: Lucian Dascalescu, Thami Zeghloul, Horia-Nicolai Teodorescu, Yopa Eka Prawatya, 'Gheorghe Asachi' Technical University of Iasi (TUIASI), Mécanique des Interfaces Lubrifiées (TriboLub), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), and FEDER - ELECTRINOV Program
Subjects: Materials science, Polymers, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], 02 engineering and technology, Surface finish, [SPI.AUTO]Engineering Sciences [physics]/Automatic, chemistry.chemical_compound, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Sliding, Anisotropy, Triboelectric effect, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], chemistry.chemical_classification, Direction-dependence, Acrylonitrile butadiene styrene, Manufacturing process, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, Surfaces and Interfaces, Polymer, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Triboelectrification, Potential profile, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Surfaces, Coatings and Films, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Polyvinyl chloride, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, chemistry, Mechanics of Materials, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], 0210 nano-technology
Abstract: International audience; The paper contributes to the understanding of triboelectric charging mechanisms. It brings evidence of the fact that in polymer slabs this effect may present significant direction dependence (anisotropy) related to the initial superficial roughness. The study was carried out on Polyvinyl Chloride (PVC) slabs in frictional sliding conformal contact with Acrylonitrile Butadiene Styrene (ABS) slices. It showed that the anisotropy of tribocharging is correlated to that of initial surface patterns (texturing) specific to polymer manufacturing process. The effect is preserved for small numbers of repeated movements even when moderate wearing occurs. Conclusions are derived for improving triboelectric energy harvesters, sensors, and other applications.
Published: 2019

37. Temperature dependence of elastic moduli in a refractory HfNbTaTiZr high-entropy alloy

Author: Guillaume Laplanche, Jean-Philippe Couzinié, Loïc Perrière, Ivan Guillot, Pascal Gadaud, ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie et des Matériaux Paris-Est (ICMPE), Institut de Chimie du CNRS (INC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), and ANR-16-CE08-0027,TURBO-AHEAD,Développement d'alliages multi-composants à haute entropie de mélange pour applications turbomachines(2016)
Subjects: TiZrNbHfTa, Materials science, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Alloy, 02 engineering and technology, engineering.material, 010402 general chemistry, Elastic constants, 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Condensed Matter::Materials Science, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Materials Chemistry, Texture, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Texture (crystalline), [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Microstructure, Elastic modulus, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, High entropy alloys, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Metals and Alloys, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Atmospheric temperature range, 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 0104 chemical sciences, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Mechanics of Materials, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], engineering, Thermomechanical processing, 0210 nano-technology, Solid solution
Abstract: International audience; The equiatomic HfNbTaTiZr solid solution is currently regarded as a model disordered body-centered cubic high-entropy alloy. Therefore, the temperature dependence of its elastic moduli is of prime importance to improve our understanding of the mechanical properties of this refractory alloy. In this study, the alloy was found to be single phase, fully recrystallized with a slight texture along the normal direction after thermomechanical processing at room temperature. Elastic moduli were determined over the temperature range [293 K-1100 K].
Published: 2019

38. Engineering the interfacial adhesion in basalt/epoxy composites by plasma polymerization

Author: Vladimir Cech, Fabienne Touchard, Fabrizio Sarasini, Laurence Chocinski-Arnault, David Mellier, Maria Paola Bracciale, Maria Carolina Seghini, Jacopo Tirillò, Milan Zvonek, Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome], ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, and Brno University of Technology [Brno] (BUT)
Subjects: Materials science, natural fibres, interface/interphase, fibre/matrix bond, CT analysis, Composite number, Plasma-Enhanced Chemical Vapor Deposition, 02 engineering and technology, engineering.material, 010402 general chemistry, 01 natural sciences, Matrix (chemical analysis), Coating, Interface/interphase, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Surface roughness, Coupling (piping), Composite material, Natural fibres : Interface/interphase, Adhesion, Epoxy, 021001 nanoscience & nanotechnology, Plasma polymerization, 0104 chemical sciences, Fibre/matrix bond, Mechanics of Materials, visual_art, Ceramics and Composites, engineering, visual_art.visual_art_medium, Basalt fibres, Fibre/matrix bond : CT analysis, 0210 nano-technology
Abstract: International audience; In an attempt to improve mechanical properties of basalt fibre/epoxy composites, the present work provides a comparison between the effects of a commercial coupling agent, a thermal de-sizing treatment and a plasma polymerization process on the fibre/matrix interfacial strength. The different basalt fibres were characterized in terms of surface morphology, by FE-SEM observations, and chemical composition, performing FT-IR analysis. The interfacial adhesion has been investigated by single fibre fragmentation test on single filament composite samples. The plasma polymerization process was able to produce a homogeneous tetravinylsilane (pp-TVS) coating on the surface of basalt fibres, which resulted in a significant increase in the fibre/matrix adhesion. The surface roughness of the untreated and treated basalt fibres has been measured by AFM and a relationship between the surface roughness and the fibre/matrix adhesion quality was found. High-resolution microtomography (µ-CT) has been used to support the analysis of the damage modes during fragmentation tests.
Published: 2019

39. Characterization of nanostructure in low dose Fe-implanted p-type 6H-SiC using atom probe tomography

Author: Jean Juraszek, A. Fnidiki, Michel Viret, Lindor Diallo, Alain Declémy, L. Lechevallier, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Physique des Défauts et de la Plasticité PDP (PDP), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Nanostructure, Annealing (metallurgy), Low dose, Analytical chemistry, Nanoclusters, 02 engineering and technology, Atom probe, Magnetic semiconductor, Spin electronics, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Microstructure, 01 natural sciences, Electronic, Optical and Magnetic Materials, law.invention, Atom probe tomography, law, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Diluted magnetic semiconductor, Rapid thermal annealing, 010306 general physics, 0210 nano-technology
Abstract: International audience; P-doped 6H-SiC substrates were implanted with Fe ions. During implantation the samples were maintained at 550 °C with energies ranging from 30 to 160 keV in order to produce a diluted magnetic semiconductor (DMS) with a 2% Fe homogeneous concentration to a depth of about 100 nm thickness. The effects of rapid thermal annealing on the microstructure were examined by atom probe tomography (APT). The study shows evidence of the formation of Fe rich nanoclusters after annealing which contain core magnetic phases that contribute to the magnetic properties.
Published: 2019

40. Analysis of the influence of averaged positive second invariant Q of deformation tensor ∇u on the maximum dilution index Emax in steady Darcy flows through isotropic heterogeneous porous media

Author: Anthony Beaudoin, Serge Huberson, Arthur Dartois, Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Hydrodynamique et Ecoulements Environnementaux (HydEE), Département Fluides, Thermique et Combustion (FTC), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers
Subjects: 010504 meteorology & atmospheric sciences, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], 0208 environmental biotechnology, 02 engineering and technology, 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Physics::Fluid Dynamics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Hydraulic conductivity, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Invariant (mathematics), 0105 earth and related environmental sciences, Water Science and Technology, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Physics, Darcy's law, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Isotropy, Mathematical analysis, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Vorticity, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 020801 environmental engineering, Dilution, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Log-normal distribution, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Porous medium
Abstract: International audience; Characterization of flow topology is essential to understand the effects of the heterogeneity and dimensionality of geological formations on the mixing of inert solute clouds in these same geological formations. In this work, we numerically study two indicators of flow topology, the averaged vorticity magnitude vertical bar omega vertical bar(av) and the averaged positive second invariant Q(av) of the deformation tensor del u, in steady Darcy flows through exponentially correlated lognormal hydraulic conductivity fields K. Our numerical results allow us to establish the relationships between the two indicators considered here and the hydraulic conductivity variance sigma(2) in 2D and 3D, highlighting the role played by the spatial structure of these porous media on flow topology, and indirectly on mixing. This work leads us to assess the maximum dilution index E-max, indicator of mixing, theoretically known to increase monotonically in steady Darcy flows through isotropic heterogeneous porous media. Our numerical results allow us to test this hypothesis by establishing the relationship between the slope a of maximum dilution index E-max and the averaged positive second invariant Q(av) of deformation tensor del u. The parameters of this relationship depend on molecular diffusion and dimensionality of problem considered.
Published: 2019

41. Evaluation of ligament laxity during pregnancy

Author: Nikolaus Veit-Rubinc, A. Decatoire, Laetitia Fradet, David Desseauve, Yosra Cherni, Mickaël Begon, Fabrice Pierre, Robotique, Biomécanique, Sport, Santé (RoBioSS), Département Génie Mécanique et Systèmes Complexes (GMSC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), School of Sport and Exercise Sciences, Loughborough University, Université de Montréal. Faculté de médecine. École de kinésiologie et des sciences de l'activité physique, and Hôpital Sainte-Justine. Centre de réadaptation Marie Enfant. Centre de recherche
Subjects: Clinical tests, Ligamentous laxity, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Metacarpophalangeal Joint, 0302 clinical medicine, Pregnancy, Back pain, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Range of Motion, Articular, [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Orthodontics, Lumbar Vertebrae, 030219 obstetrics & reproductive medicine, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Obstetrics and Gynecology, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 3. Good health, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, medicine.anatomical_structure, 030220 oncology & carcinogenesis, Hypermobility, Female, Hip Joint, Pregnancy Trimesters, Analysis of variance, medicine.symptom, Adult, Ligament Laxity, [SPI.AUTO]Engineering Sciences [physics]/Automatic, 03 medical and health sciences, Lumbar, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Quantification, medicine, Humans, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], business.industry, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Metacarpophalangeal joint, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], medicine.disease, [CHIM.POLY]Chemical Sciences/Polymers, Reproductive Medicine, Case-Control Studies, Exercise Test, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Extensometer, business
Abstract: International audience; OBJECTIVE:Pregnancy-related changes in ligament laxity have been shown to be associated with various disorders such as back pain or pelvic floor disorders. The purpose of this study was to assess laxity changes during pregnancy by confronting different methods in order to suggest a simple clinical tool helping to prevent the aforementioned problems.DESIGN:Seventeen pregnant women were evaluated at the first, second and third trimesters as cases and 16 non-pregnant women participated as controls. Ligamentous laxity was measured using an extensometer for the metacarpophalangeal joint of the index, a fingertip to floor test and a sit and reach test to assess hip and lumbar flexibility and the Beighton score. Statistical analysis included independent samples t-tests, analysis of variance and Pearson correlation coefficients.RESULTS:Laxity of the metacarpophalangeal joint increased by 11% from the first to the second trimester of pregnancy and stabilized until delivery. The Beighton score was significantly higher in the second trimester of pregnancy (p
Published: 2019

42. Comparison of falling dart and Charpy impacts performances of compatibilized and not compatibilized polypropylene/woven glass fibres composites

Author: Giorgio Simeoli, Maria Oliviero, Pietro Russo, David Mellier, Fabienne Touchard, Luigi Sorrentino, Istituto per i Polimeri, Compositi e Biomateriali (IPCB), Consiglio Nazionale delle Ricerche (CNR), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), and ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers
Subjects: Materials science, Charpy impact test, Interface strenght, Charpy impact, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, Slip (ceramics), Industrial and Manufacturing Engineering, chemistry.chemical_compound, Flexural strength, Woven fabric, [SPI.MECA.MEMA]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of materials [physics.class-ph], Coupling (piping), Glass fibres, Falling dart impact, Composite material, computer.programming_language, chemistry.chemical_classification, Polypropylene, Dart, Mechanical Engineering, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Interface strength, Thermoplastic composites, chemistry, Mechanics of Materials, visual_art, Ceramics and Composites, visual_art.visual_art_medium, Thernoplastic composites, 0210 nano-technology, computer
Abstract: International audience; The effect of the matrix/fibre interface strength on the in-plane and out-of-plane impact performances of glass woven fabric/polypropylene laminates, prepared by means of film stacking technique, was investigated. The interface strength between polymer and fibres was varied by means of a coupling agent added to two different polypropylene grades in order to evaluate its contribution to the impact resistance of the laminates. The static characterization showed that the flexural strength of compatibilized laminates was higher with respect to that of composites based on neat matrices. On the contrary, composites with low interface strength between fibres and polymer showed a strong improvement in impact resistance, in both Charpy and falling dart impact tests. This was related to the possibility of fibres to slip into the matrix and dissipate energy through friction, and to the improved capability to bear load before fibre failure, allowed by the limited propagation of cracks through the laminate. The damage after impact was assessed by means of micro-computed tomography, which elucidated the role of the weak matrix/fibre interface in improving the impact resistance.
Published: 2019

43. Study of Two-Stage-Type Electrostatic Precipitator in Axisymmetric Configuration Applied to Finely Ground Lignocellulosic Materials

Author: Claire Mayer-Laigle, Xavier Rouau, F. Kherbouche, Lucien Dascalescu, Ayyoub Zouaghi, Noureddine Zouzou, Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Ingénierie des Agro-polymères et Technologies Émergentes (UMR IATE), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA), University Mustapha Stambouli [Mascara], Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA, Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Institut Pprime (PPRIME), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA-Université de Poitiers-Centre National de la Recherche Scientifique (CNRS)-ENSMA, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Université Montpellier 2 - Sciences et Techniques (UM2)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université Montpellier 2 - Sciences et Techniques (UM2)-Université de Montpellier (UM)-Institut National de la Recherche Agronomique (INRA), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: procédé agroalimentaire, Materials science, 0211 other engineering and technologies, Rotational symmetry, Electrostatic hazards, Electrostatic precipitator, 02 engineering and technology, broyage, 01 natural sciences, Finely ground lignocellulosic materials, Industrial and Manufacturing Engineering, 010305 fluids & plasmas, Ion, lignocellulose, [SDV.IDA]Life Sciences [q-bio]/Food engineering, 0103 physical sciences, Corona discharge, [SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering, 021108 energy, Electrical and Electronic Engineering, 010302 applied physics, Waste management, Mechanics, 021001 nanoscience & nanotechnology, grinding, Grinding, Triode-type electrodes, electrostatic interaction, Control and Systems Engineering, Electrode, Electrostatic precipitators, Particle, Stage (hydrology), Particle size, Electric potential, 0210 nano-technology, Particle collection efficiency, interaction électrostatique
Abstract: The main objective of this paper is to develop a novel two-stage-type electrostatic precipitator to collect finely ground lignocellulosic particles. To prevent the danger of explosion of such a powdery material, ion generation and particle charging processes are separated. Main results show that the particles can be highly charged in a two-coaxial-cylinders triode-type device, which also facilitates their collection. For instance, the collection efficiency reaches 92 % for particle size of about 0.3 μm, and exceeds 99% for particle size greater than 2 μm.
Published: 2019

44. A normalised residence time transport equation for the numerical simulation of combustion with high-temperature air

Author: Xiaodong Wang, Vincent Robin, Arnaud Mura, Structures de flammes et Combustion (CT ), Département Fluides, Thermique et Combustion (FTC), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: self-ignition, General Chemical Engineering, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], General Physics and Astronomy, Energy Engineering and Power Technology, highly preheated air stream, STREAMS, Combustion, Residence time (fluid dynamics), 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, 010305 fluids & plasmas, Physics::Fluid Dynamics, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], non-premixed combustion, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Physics::Chemical Physics, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], residence time, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], 010304 chemical physics, Computer simulation, Turbulence, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, General Chemistry, Mechanics, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], turbulence-chemistry interaction, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Fuel Technology, Modeling and Simulation, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Environmental science, Convection–diffusion equation
Abstract: International audience; This study concerns the numerical simulation of turbulent non-premixed combustion in highly preheated air streams. One of the objectives is to settle an efficient computational procedure to proceed with the numerical simulation of large-scale industrial devices. It is also expected that the availability of such a computational framework may facilitate comprehensive sensitivity analyses as well as the development of mathematical models able to represent turbulence-chemistry interactions (TCI) in such conditions. Based on the salient physical ingredients that characterise scalar mixing, propagation, and self-ignition processes, a turbulent combustion modelling framework is thus introduced and applied to the numerical simulation of well-documented laboratory flames. In the corresponding geometries, the bulk flow velocities of the reactants streams can reach rather large values, which lead the flame to lift from the burner rim. Partially premixed flame edges thus stabilise the whole flame structure and the temperature of the oxidising stream can be increased by vitiation with burned gases so as to promote the corresponding flame-stabilisation processes. For sufficiently large values of the vitiated airstream temperature, self-ignition mechanisms may be triggered thus leading to a competition between mixing, propagation, and ignition processes. In this context, the ratio of the residence time to the self-ignition delay is thought to be a relevant variable to delineate the possible influence of ignition phenomena. Therefore, a modelled transport equation for this normalised residence time is considered. The performance of the corresponding modelling proposal is analysed with special emphasis placed on its ability to reproduce ‘memory’ or ‘lagrangian’ effects related to thermal aging processes. In this respect, it is noteworthy that the present set of computations makes use of tabulated quantities associated to (i) steady laminar one-dimensional diffusion flamelets, so as to describe the composition of combustion products, (ii) steady laminar one-dimensional premixed flamelets, to describe the flame brush propagation, and (iii) temporal evolution of zero-dimensional homogeneous mixtures to account for the possible occurrence of self-ignition phenomena. In particular, the tabulated self-ignition time value is used to evaluate the increase in the normalised residence time. Finally, two modelling parameters are put into evidence and studied through a detailed sensitivity analysis.
Published: 2019

45. Assessment of a damage model for wound composite structures by acoustic emission

Author: Juan Pedro Berro Ramirez, Damien Halm, Jean-Claude Grandidier, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), and ANR-09-HPAC-0010,OSIRHYS IV,Outils de SImulation du comportement des Réservoir de stockage d'HYdrogène Spécifiques au type IV(2009)
Subjects: Materials science, Acoustics, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Composite number, Wound composite, 02 engineering and technology, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Acoustic emission, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, otorhinolaryngologic diseases, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Continuous evolution, Civil and Structural Engineering, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Finite element analysis, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, Finite element method, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Ceramics and Composites, Damage model, 0210 nano-technology
Abstract: International audience; This paper deals with the link between the acoustic activity due to damage in wound composite structures and the simulated evolution of damage variables. A damage model able to accurately capture the different degradation modes which may occur in this type of material is first selected. A parallel is drawn between the continuous evolution of the damage variables and the discrete acoustic events. The mechanical behaviour of notched samples made of two different wound composite lay-ups and involving complex damage combinations are simulated and compared to acoustic emission. The satisfactory correlation confirms the physical meaning of the damage variables and validates the model assumptions. The association of experimental acoustic signals and a damage model is a tool to understand the degradation scenario of wound composite structures and the meaning of the recorded acoustic events.
Published: 2019

46. Atomic-scale diffusion rates during growth of thin metal films on weakly-interacting substrates

Author: Jamnig, A., Sangiovanni, D. G., Abadias, G., Sarakinos, K., Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, Physique et Propriétés des Nanostructures PPNa (PPNa), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-Institut Pprime (PPRIME), ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers, and ANR-11-LABX-0017,INTERACTIFS,Interactions and transfers at fluids and solids interfaces(2011)
Subjects: Silver, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Surface_Diffusion, lcsh:Medicine, Article, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Clusters, Condensed Matter::Materials Science, Surfaces, interfaces and thin films, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Deposition, lcsh:Science, Microstructure, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Molecular-Dynamics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, lcsh:R, AG, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Condensed Matter Physics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Design, synthesis and processing, Stress evolution, Nuclaetion, [CHIM.POLY]Chemical Sciences/Polymers, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], lcsh:Q, Den kondenserade materiens fysik, CU
Abstract: We use a combined experimental and theoretical approach to study the rates of surface diffusion processes that govern early stages of thin Ag and Cu film morphological evolution on weakly-interacting amorphous carbon substrates. Films are deposited by magnetron sputtering, at temperatures TS between 298 and 413 K, and vapor arrival rates F in the range 0.08 to 5.38 monolayers/s. By employing in situ and real-time sheet-resistance and wafer-curvature measurements, we determine the nominal film thickness Θ at percolation (Θperc) and continuous film formation (Θcont) transition. Subsequently, we use the scaling behavior of Θperc and Θcont as a function of F and Ts, to estimate, experimentally, the temperature-dependent diffusivity on the substrate surface, from which we calculate Ag and Cu surface migration energy barriers \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{E}}}_{{\boldsymbol{D}}}^{{\bf{\exp }}}$$\end{document}EDexp and attempt frequencies \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{\nu }}}_{{\bf{0}}}^{{\bf{\exp }}}$$\end{document}ν0exp. By critically comparing \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{E}}}_{{\boldsymbol{D}}}^{{\bf{\exp }}}$$\end{document}EDexp and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{\nu }}}_{{\bf{0}}}^{{\bf{\exp }}}$$\end{document}ν0exp with literature data, as well as with results from our ab initio molecular dynamics simulations for single Ag and Cu adatom diffusion on graphite surfaces, we suggest that: (i) \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{E}}}_{{\boldsymbol{D}}}^{{\bf{\exp }}}$$\end{document}EDexp and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${{\boldsymbol{\nu }}}_{{\bf{0}}}^{{\bf{\exp }}}$$\end{document}ν0exp correspond to diffusion of multiatomic clusters, rather than to diffusion of monomers; and (ii) the mean size of mobile clusters during Ag growth is larger compared to that of Cu. The overall results of this work pave the way for studying growth dynamics in a wide range of technologically-relevant weakly-interacting film/substrate systems—including metals on 2D materials and oxides—which are building blocks in next-generation nanoelectronic, optoelectronic, and catalytic devices.
Published: 2019

47. Fine particle removal by a two-stage electrostatic precipitator with multiple ion-injection-type prechargers

Author: Bangwoo Han, Myungjoon Kim, Hak-Joon Kim, Yong Jin Kim, Chang Gyu Woo, Ayyoub Zouaghi, Noureddine Zouzou, School of Mechanical Engineering, Sungkyunkwan University [Suwon] (SKKU), Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: Atmospheric Science, Environmental Engineering, Materials science, 010504 meteorology & atmospheric sciences, Parallel collection plates Corrosive conditions, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Electrostatic precipitator, 010501 environmental sciences, 01 natural sciences, 7. Clean energy, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Ion, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Carbon brush, Electric field, Duct (flow), [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, 0105 earth and related environmental sciences, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Fluid Flow and Transfer Processes, business.industry, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Pollution, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Volumetric flow rate, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Semiconductor, Ion-injection-type charging stage, Electrode, Two-stage electrostatic precipitator (ESP), [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], discharge electrode, business, Voltage
Abstract: International audience; A novel two-stage electrostatic precipitator (ESP) with multiple ion injection type chargers and parallel collection plates was developed and shown to efficiently collect particles from the corrosive waste gas discharged from semiconductor and optoelectronic processes. Multiple carbon brush electrodes for the generation of ions were located outside of the main gas flow, but the injection of clean air and induced voltage between the outer and inner plates of the charging stage carried ions into the main gas flow; thus, gases and particles in the main flow did not corrode or contaminate the charger. The particle collection performance of the ESP was evaluated experimentally for 0.3 μm particles, PM (Particular matter) 10, and PM 2.5 by varying the application voltages to the charging stage, main gas flow rate, and distance of the carbon brush discharge electrode from the main gas flow duct. The novel ESP achieved particle collection efficiency of 89.5% and 99.5% at the best condition when the voltage was applied to only the charging stage and to both the charging and collection stages, respectively. The particle collection efficiency of the charging stage only and the two-stage ESP was characterized according to the corona discharge power and main flow rate based on Deutsch's collection theory. Also, a simplified 2D simulation results show that the electric field is very high not only near outer carbon fibers but also near the outer metallic electrode edge.
Published: 2019

48. Hydrogen-affected fatigue crack propagation at various loading frequencies and gaseous hydrogen pressures in commercially pure iron

Author: Gilbert Hénaff, Damien Halm, Guillaume Benoit, Giovambattista Bilotta, Mandana Arzaghi, Tomoki Shinko, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), and Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)
Subjects: Materials science, Hydrogen, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], chemistry.chemical_element, 02 engineering and technology, Industrial and Manufacturing Engineering, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Brittleness, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, Fatigue crack propagation, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Stress intensity factor, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Crack tip plasticity, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Mechanical Engineering, [SPI.NRJ]Engineering Sciences [physics]/Electric power, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], Paris' law, 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Intergranular fracture, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, chemistry, Mechanics of Materials, Modeling and Simulation, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Grain boundary, 0210 nano-technology, Hydrogen embrittlement, Commercially pure iron, Microvoid coalescence
Abstract: International audience; Hydrogen-Affected Fatigue Crack Growth (HAFCG) in commercially pure iron has been characterized in terms of hydrogen gas pressure, loading frequency and stress intensity factor range ΔK. A higher hydrogen gas pressure decreases the critical value of ΔK triggering the HAFCG enhancement, and a lower loading frequency increases the HAFCG enhancement. Intergranular FCG in the non-accelerated regime is likely caused by the hydrogen-induced microvoid coalescence along the grain boundary, while a brittle cyclic cleavage fracture in the accelerated regime can be explained in terms of crack tip sharpening and hydrogen-enhanced decohesion process.
Published: 2019

49. Extrapolation to zero frequency with first time constant of ferri-ferrocyanide/Pt interface using Foster equivalent circuit and factorized modelling

Author: V.A. Raileanu Ilie, P. Lagonotte, A. Thomas, Serguei Martemianov, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Electro-Fluido-Dynamique (EFD ), Département Fluides, Thermique et Combustion (FTC), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Centre de Recherches sur les Macromolécules Végétales (CERMAV ), and Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: Identification, General Chemical Engineering, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Extrapolation, Pole–zero plot, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, [SPI.AUTO]Engineering Sciences [physics]/Automatic, Analytical Chemistry, Zero frequency extrapolation, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Foster's modelling, Electrochemistry, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Time domain, [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Electrical impedance, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], First-time constant Ferri-ferrocyanide Electrochemical systems, Chemistry, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, Mathematical analysis, Time constant, DC resistance, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 0104 chemical sciences, Dielectric spectroscopy, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, Low-frequency parameters, Frequency domain, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Equivalent circuit, 0210 nano-technology
Abstract: International audience; An estimation of low frequency parameters at the interface of a ferri-ferrocyanide solution on a Pt rotating disk electrode is presented. The determination of the total resistance and effective (low frequency) capacity is based on a Foster's model extrapolation using electrochemical impedance spectroscopy measurements. The feasibility of the proposed approach has been demonstrated at equilibrium conditions and under two polarization points. Results show a good agreement with the identified and experimental values particularly in the extra-low frequency domain. Results also demonstrate that using factorized expression (poles and zeros) of the impedance allow the stability of the identified parameters and the calculation of the first time-constant of the system. Consequently, Foster's models as equivalent to Voight-type equivalent circuit can be used for the zero frequency extrapolation and predict the response of the interface in time domain that it is certainly useful for practical electrochemical systems.
Published: 2019

50. Failure mode analysis of SMAW welded UNS N08028 (Alloy28) superaustenitic stainless steel under crack growth tests

Author: Khaled Elleuch, Veronique Pelosin, Gilbert Hénaff, Y. Kchaou, Nader Haddar, Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), ENDOmmagement et durabilité ENDO (ENDO), Département Physique et Mécanique des Matériaux (Département Physique et Mécanique des Matériaux), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS)-Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), École Nationale d'Ingénieurs de Sfax | National School of Engineers of Sfax (ENIS), and Université de Sfax - University of Sfax
Subjects: Materials science, Scanning electron microscope, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Shielded metal arc welding, 020101 civil engineering, 02 engineering and technology, Welding, [SPI.AUTO]Engineering Sciences [physics]/Automatic, 0201 civil engineering, law.invention, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], 0203 mechanical engineering, law, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.BIOM]Physics [physics]/Mechanics [physics]/Biomechanics [physics.med-ph], Composite material, Joint (geology), Base metal, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, [SPI.NRJ]Engineering Sciences [physics]/Electric power, technology, industry, and agriculture, General Engineering, [CHIM.MATE]Chemical Sciences/Material chemistry, [PHYS.MECA.MSMECA]Physics [physics]/Mechanics [physics]/Materials and structures in mechanics [physics.class-ph], respiratory system, Intergranular corrosion, Paris' law, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, [CHIM.POLY]Chemical Sciences/Polymers, 020303 mechanical engineering & transports, [PHYS.MECA.THER]Physics [physics]/Mechanics [physics]/Thermics [physics.class-ph], Failure mode and effects analysis
Abstract: International audience; The Fatigue Crack Growth (FCG) behavior of welded UNS N08028 (Alloy28) superaustenitic stainless steel was investigated in this paper. Alloy28 superaustenitic stainless steel was welded using Shielded Metal Arc Welding process. The FCG behavior was studied under two load ratios (0.1 and 0.5) and for different specimen configuration: Base Metal (BM), Weld Metal (WM) and Welded Joint (WJ). The results indicated that FCG rates of WM specimen is lower than BM specimen at R = 0.1. Moreover, load ratio affects the FCG rate for BM and WM specimen. In addition, the observation of fatigue crack growth path of WM displayed that crack follows dendritic orientation giving a tortuous crack path, while it is less tortuous for BM specimens. Scanning Electron Microscope (SEM) observations of BM fractured surfaces showed that damage mechanism is intergranular for lower ΔK value, and transgranular for higher ΔK value. Moreover, SEM observations of WM fractured surface showed the presence of welding defects which can affect negatively fatigue crack growth resistance at R = 0.5.
Published: 2019

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