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516 results on '"Ondes et Imagerie (O'

1. A finite-volume approach to 1D nonlinear elastic waves: Application to slow dynamics

Author

Guillaume Chiavassa, Nicolas Favrie, Bruno Lombard, Harold Berjamin, Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Ecole Centrale de Marseille ( ECM ), Institut universitaire des systèmes thermiques industriels ( IUSTI ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mécanique, Modélisation et Procédés Propres (M2P2), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Institut universitaire des systèmes thermiques industriels (IUSTI), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Lombard, Bruno, Ondes et Imagerie (O&I), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Acoustics and Ultrasonics, SCHEMES, PROPAGATION, 01 natural sciences, 010305 fluids & plasmas, MEDIA, symbols.namesake, Linearization, INTERNAL VARIABLES, 0103 physical sciences, 010301 acoustics, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Physics, DAMAGE, Conservation law, [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], Finite volume method, [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], Numerical analysis, Mathematical analysis, Equations of motion, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Nonlinear system, Riemann problem, symbols, Flux limiter, Music
Abstract

International audience; A numerical method for longitudinal wave propagation in nonlinear elastic solids is presented. Here, we consider polynomial stress-strain relationships, which are widely used in nondestructive evaluation. The large-strain and infinitesimal-strain constitutive laws deduced from Murnaghan's law are detailed , and polynomial expressions are obtained. The Lagrangian equations of motion yield a hyperbolic system of conservation laws. The latter is solved numerically using a finite-volume method with flux limiters based on Roe linearization. The method is tested on the Riemann problem, which yields nonsmooth solutions. The method is then applied to a continuum model with one scalar internal variable, accounting for the softening of the material (slow dynamics).

Published
2018

2. Acoustical properties of compressed earth blocks: Effect of compaction pressure, water hyacinth ash and lime

Author

Justus Ouma, Nicholas Ongwen, Erick Ogam, Mercy Auma, Z.E.A. Fellah, Maxwell Mageto, Mohamed Ben Mansour, Andrew Oduor, Department of Physics and Materials Science, Maseno University, Maseno, Kenya, Tom Mboya University College (TMUC), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Masinde Muliro University of Science and Technology [Kakamega, Kenya], Laboratoire d'Energétique et des Transferts Thermique et Massique de Tunis, Faculté des Sciences de Bizerte [Université de Carthage], Université de Carthage - University of Carthage-Université de Carthage - University of Carthage, and DERCI AMOI CNRS

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI]Engineering Sciences [physics], Materials Science (miscellaneous), Compressed earth blocks, Acoustics of compressed earth blocks, Water hyacinth in compressed earth blocks, Lime-stabilized earth blocks
Abstract

International audience; This study assessed the potential use of a mixture of lime and water hyacinth ash (WHA) as binders in fabrication of cylindrical compressed earth blocks (CEBs) with good acoustic absorption properties for building and construction. Different concentrations of the binders and compaction pressures were employed so as to vary the acoustical properties of the fabricated blocks. The geometric and transport parameters of their porous microstructure were recovered through probing using acoustic waves. A low-frequency acoustic wave guide was built for this purpose. It was found out that the transmission coefficient decreased with the compaction pressure, and with addition of lime, while WHA increased the transmission coefficient. The non-acoustical parameters recovered using the equivalent fluid model (JCAL) showed that the variation of the geometry of the microstructure of the blocks is what influences the acoustic transmission coefficient. Thus, the properties of the CEBs can be steered using binder concentration and compaction pressure in a controlled manner.

Published
2023

3. A Generalization of Poiseuille’s Law for the Flow of a Self-Similar (Fractal) Fluid through a Tube Having a Fractal Rough Surface

Author

Abdellah Bouchendouka, Zine El Abiddine Fellah, Zakaria Larbi, Nicholas O. Ongwen, Erick Ogam, Mohamed Fellah, Claude Depollier, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Maseno University, Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT), Laboratoire d'Acoustique de l'Université du Mans (LAUM), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, [SPI]Engineering Sciences [physics], fractal tube surface, self-similar fluid, noninteger dimensional spaces, Poiseuille’s law, Statistical and Nonlinear Physics, Navier–Stokes equations for fractal medium, surface fractal dimensions, Analysis
Abstract

In this paper, a generalization of Poiseuille’s law for a self-similar fluid flow through a tube having a rough surface is proposed. The originality of this work is to consider, simultaneously, the self-similarity structure of the fluid and the roughness of the tube surface. This study can have a wide range of applications, for example, for fractal fluid dynamics in hydrology. The roughness of the tube surface presents a fractal structure that can be described by the surface fractal noninteger dimensions. Complex fluids that are invariant to changes in scale (self-similar) are modeled as a continuous medium in noninteger dimensional spaces. In this work, the analytical solution of the Navier–Stokes equations for the case of a self-similar fluid flow through a rough “fractal” tube is presented. New expressions of the velocity profiles, the fluid discharge, and the friction factor are determined analytically and plotted numerically. These expressions contain fractal dimensions describing the effects of the fractal aspect of the fluid and of that of the tube surface. This approach reveals some very important results. For the velocity profile to represent a physical solution, the fractal dimension of the fluid ranges between 0.5 and 1. This study also qualitatively demonstrates that self-similar fluids have shear thickening-like behavior. The fractal (self-similarity) nature of the fluid and the roughness of the surface both have a huge impact on the dynamics of the flow. The fractal dimension of the fluid affects the amplitude and the shape of the velocity profile, which loses its parabolic shape for some values of the fluid fractal dimension. By contrast, the roughness of the surface affects only the amplitude of the velocity profile. Nevertheless, both the fluid’s fractal dimension and the surface roughness have a major influence on the behavior of the fluid, and should not be neglected.

Published
2023

4. Ultrasonic and acoustic localization and characterization in complex environments

Author

Rakotonarivo, Sandrine T., Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), ED 353 Sciences pour l’ingénieur : Mécanique, Physique, Micro et Nanoélectronique, and Philippe Roux

Subjects
contrôle non desctructif, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], underwater acoustics, Acoustic imaging, Imagerie acoustique, acoustique sous-marine, ultrasound, ultrasons, non-destructive testing
Abstract

The research work presented in this manuscript concerns the development of ultrasonic and acoustic methods for source localization (1st axis) and the characterization of complex structures and objects in complex environments (2nd axis). These researches have been carried out mainly for non-destructive testing and underwater acoustics applications. The development of methods of localization and characterization is based on the resolution of a problem of Signal to Noise Ratio (SNR) which can be maximized by the use of low noise measurement devices with as many sensors as possible, or by measurements in a simple environment, that is to say, isotropic, homogeneous, infinite and low attenuation. However, in the various applications inspected in this work, the SNR is compromised because the inspected structure or the inspected environment are generally finite and attenuating, and depending on the case, may be anisotropic (e.g., multi-pass welding), reverberant (marine waveguide) and diffuse (concrete specimen). In this case, the signature of the source to be located or the object to be characterized is masked by the drop in amplitude caused by attenuation, possible beam deviations related to anisotropy or multiple interactions of the wave with the medium (multiple reflections or reverberation with the edges of the medium, diffraction and scattering by diffusers). In addition, the inverse problems of localization and characterization are affected by the access to limited information of the medium due to the limitation of measurements for reasons of experimental implementation. Different strategies based on a perturbative approach have been adopted to localize a source or characterize a complex structure in such environments. In the presence of sufficient a priori knowledge to develop a numerical model of the inspected environment, a parametric approach based on the topological energy method and then the matched filtering are examined. In the opposite case of low level of a priori information, a data based strategy is adopted for feeding the forward problem with measurements and approaches of beamforming, matched filtering, field correlation, interferometry and sensitivity kernels are implemented.In the framework of my second research project on characterization in diffuse media, I examined two problematics. The first one concerns the characterization of a diffuse medium for civil engineering applications for the monitoring and evaluation of damage at the earliest possible stage of concrete structures from the analysis of the first and second order moments of the ultrasonic field. While the second problematic concernes the characterization of a radiating elastic object immersed in a diffuse field. In this context, the approach is based on the analysis of the coherence between sensors combined with acoustic holography methods.; Les travaux de recherches présentés dans ce manuscrit portent sur le développement de méthodes ultrasonores et acoustiques à des fins de localisation de sources (1er axe) et de la caractérisation de structures complexes et d'objets en environnements complexes (2ème axe). Ces recherches ont été menées principalement pour des applications en contrôle non destructif et en acoustique sous-marine. Le développement de méthodes de localisation et caractérisation repose sur la résolution d'un problème de Rapport Signal sur Bruit (RSB) qui peut être maximisé par l'utilisation de dispositifs de mesure peu bruités et comportant le plus possible de capteurs de mesures, ou par des mesures dans un environnement simple, c'est-à-dire isotrope, homogène, infini et peu atténuant. Or dans les différentes applications inspectées dans ces travaux, le RSB est mis à mal car la structure inspectée ou le milieu ausculté sont généralement finis et atténuants, et selon le cas, peuvent être anisotropes (par exemple, soudure multi-passe), réverbérants (guide d'onde marin) et diffus (éprouvette de béton). Dans ce cas, la signature de la source à localiser ou de l'objet à caractériser se trouve masquée par la baisse d'amplitude engendrée par l'atténuation, les possibles déviations de faisceau liées à l'anisotropie ou les interactions multiples de l'onde avec le milieu (réflexion multiples ou réverbération avec les bords du milieu, diffraction et diffusion par des diffuseurs). Par ailleurs, les problèmes inverses de localisation et caractérisation se trouvent affectés par l'accès à une information limitée du milieu du fait de la limitation des prises de mesures pour des raisons de mise en oeuvre expérimentale. Différentes stratégies reposant sur une approche perturbative ont été adoptées pour localiser une source ou caractériser une structure complexe dans de tels environnements. En présence de connaissances a priori suffisantes pour élaborer un modèle numérique du milieu inspecté, une démarche paramétrique basée sur la méthode de l'énergie topologique puis le filtrage adapté est adoptée. Dans le cas contraire (faible niveau d'information a priori), la stratégie adoptée est axée sur l'alimentation du problème direct à partir de la mesure en mettant en oeuvre des approches de formation de voies, de filtrage adapté, de corrélation de champ, d'interférométrie ou basée sur les noyaux de sensibilité.Dans le cadre de mon deuxième volet de recherche sur la caractérisation en milieu diffus, je me suis intéressée notamment à deux problematiques. La première concerne la caractérisation d'un milieu lui-même diffus pour des applications en génie civil pour le suivi et l'évaluation de l'endommagement à un stade le plus précoce possible de structures en béton à partir de l'analyse des moments d'ordre 1 et 2 du champs ultrasonore. Tandis que la deuxième problématique inspectée est celle de la caractérisation d'un objet élastique rayonnant immergé dans un champ diffus. Dans ce cadre, l'approche repose sur l'analyse de la cohérence entre capteurs combinée à des méthodes d'holographie acoustique.

Published
2023

5. Thermal properties and pressure-dependent elastic constants of cadmium stannate as a substrate for MEMS: An ab initio study

Author

Nicholas Ongwen, Erick Ogam, Z.E.A. Fellah, Maxwell Mageto, Herrick Othieno, Henry Otunga, Department of Physics and Materials Science, Maseno University, Maseno, Kenya., Tom Mboya University College (TMUC), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Masinde Muliro University of Science and Technology [Kakamega, Kenya], Department of Physics and Materials Science, Maseno University, Maseno, Kenya, Maseno University, Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Masinde Muliro University of Science and Technology

Subjects
History, Pressure-dependent elastic constants, Thermal properties, Polymers and Plastics, Ductile MEMS substrates, Cadmium stannate, Condensed Matter Physics, Industrial and Manufacturing Engineering, Electronic, Optical and Magnetic Materials, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], Thermal properties of cadmium stannate, Substrates for MEMS, Electrical and Electronic Engineering, Business and International Management
Abstract

International audience; Silicon carbide (SiC) has become a suitable replacement to silicon as a substrate for manufacture of microelectromechanical systems (MEMS) that operate in harsh environmental conditions, owing to its better mechanical properties such as excellent wear resistance. However, just like silicon, SiC is also brittle, a property that limits its application as a substrate for manufacture of flexible MEMS. In this study, we explored the thermal properties as well as the pressure-dependent elastic constants of cadmium stannate (Cd2SnO4) for the first time within the quantum espresso code. The result showed that the elastic constants of SiC are much higher than those of Cd2SnO4. The properties of SiC were found to be more sensitive to the applied pressure compared those of Cd2SnO4, implying that it is less mechanically and thermally stable with the applied pressure compared to Cd2SnO4, and therefore, less appealing compared to Cd2SnO4 for the manufacture of most MEMS.

Published
2023

6. Multiphase Composites Obtained by Sintering Reaction of Boehmite and Zircon Part I: Development and Microstructural Characterization (Retraction of vol 46, pg 291, 2014)

Author

Belhouchet, H., Makri, H., Hamidouche, M., Bouaouadja, N., Garnier, V., Fantozzi, Gilbert, Laboratoire des Matériaux Non Métalliques, Université Ferhat-Abbas Sétif 1 [Sétif] (UFAS1), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), 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 Ferhat-Abbas [Sétif] ( UFAS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), 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 ), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[ SPI.MAT ] Engineering Sciences [physics]/Materials, ComputingMilieux_MISCELLANEOUS, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience

Published
2015

7. Flow of a Self-Similar Non-Newtonian Fluid Using Fractal Dimensions

Author

Abdellah Bouchendouka, Zine El Abiddine Fellah, Zakaria Larbi, Nicholas O. Ongwen, Erick Ogam, Mohamed Fellah, Claude Depollier, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Materials Science, Maseno University, Maseno, Kenya, Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT), Laboratoire d'Acoustique de l'Université du Mans (LAUM), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Statistics and Probability, fractal dimensions, power-law fluid, non-Newtonian fluid, self-similar fluid, noninteger dimensional space, Statistical and Nonlinear Physics, Fractal dimension, Analysis, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; In this paper, the study of the fully developed flow of a self-similar (fractal) power-law fluid is presented. The rheological way of behaving of the fluid is modeled utilizing the Ostwald–de Waele relationship (covering shear-thinning, Newtonian and shear-thickening fluids). A self-similar (fractal) fluid is depicted as a continuum in a noninteger dimensional space. Involving vector calculus for the instance of a noninteger dimensional space, we determine an analytical solution of the Cauchy equation for the instance of a non-Newtonian self-similar fluid flow in a cylindrical pipe. The plot of the velocity profile obtained shows that the rheological behavior of a non-Newtonian power-law fluid is essentially impacted by its self-similar structure. A self-similar shear thinning fluid and a self-similar Newtonian fluid take on a shear-thickening way of behaving, and a self-similar shearthickening fluid becomes more shear thickening. This approach has many useful applications in industry, for the investigation of blood flow and fractal fluid hydrology

Published
2022
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8. Accurate Ab-initio calculation of elastic constants of anisotropic binary alloys: A case of Fe–Al

Author

Nicholas O. Ongwen, Erick Ogam, Z.E.A. Fellah, Henry O. Otunga, Andrew O. Oduor, Maxwell Mageto, Department of Physics and Materials Science, Maseno University, Maseno, Kenya, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Materials Science, Maseno University, Maseno, Kenya., and Masinde Muliro University of Science and Technology [Kakamega, Kenya]

Subjects
Materials Chemistry, General Chemistry, Condensed Matter Physics, ComputingMilieux_MISCELLANEOUS, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience

Published
2022

9. Low temperature synthesis of ultrafine non vermicular alpha-alumina from aerosol decomposition of aluminum nitrates salts

Author

Elisabeth Djurado, Yann Aman, Cécile Rossignol, Vincent Garnier, Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces (LEPMI ), Institut de Chimie du CNRS (INC)-Institut National Polytechnique de Grenoble (INPG)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Université Joseph Fourier - Grenoble 1 (UJF)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Université Claude Bernard Lyon 1 (UCBL), 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), Laboratoire d'Electrochimie et de Physico-chimie des Matériaux et des Interfaces ( LEPMI ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut National Polytechnique de Grenoble ( INPG ) -Université Savoie Mont Blanc ( USMB [Université de Savoie] [Université de Chambéry] ) -Centre National de la Recherche Scientifique ( CNRS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), 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 ), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Institut de Chimie du CNRS (INC)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, [ SPI.MAT ] Engineering Sciences [physics]/Materials, Inorganic chemistry, alpha-alumina, 02 engineering and technology, 010402 general chemistry, 01 natural sciences, law.invention, [SPI.MAT]Engineering Sciences [physics]/Materials, law, Differential thermal analysis, Materials Chemistry, Calcination, Ultrasonic spray pyrolysis, Aqueous solution, Aluminum nitrates, 021001 nanoscience & nanotechnology, Microstructure, 0104 chemical sciences, Amorphous solid, Thermogravimetry, Chemical engineering, Ceramics and Composites, 0210 nano-technology, Pyrolysis, BET theory, alpha-phase transformation
Abstract

International audience; In this paper, spherical, smooth and unagglomerated ultrafine amorphous powder particles were prepared by ultrasonic spray pyrolysis (USP) of easy-handling aqueous aluminum nitrate salts increasing the precursor solute concentration to 0.5 mol L-1 and reducing the pyrolysis temperature to 700 degrees C. The transformation of the USP alumina powders into alpha-Al2O3 was studied using combination of X-ray diffraction, electron microscopy, infrared spectroscopy, BET surface area, thermogravimetry and differential thermal analysis. A downward shift of the onset temperature of alpha-phase transformation to 900 degrees C has been detected using a larger precursor solution concentration and performing a milling before calcination due to an increase in the surface density of defects, in surface area and in anisotropic particle shape. Additional post-milling of the low calcined powders allowed the preparation of agglomerate-free pure ultrafine alpha-Al2O3 powder particles (similar to 100 nm, 28 m(2) g(-1)), free of vermicular microstructures. (C) 2013 Elsevier Ltd. All rights reserved.

Published
2013

10. Highly Dense, Transparent-Al2O3 Ceramics From Ultrafine Nanoparticles Via a Standard SPS Sintering

Author

Vincent Garnier, Jean-Yves Chane-Ching, G. Bonnefont, Sophie Guillemet-Fristch, Domingo I. Garcia-Gutierrez, Sandrine Trombert, Lionel Bonneau, Bernard Durand, Nicolas Roussel, Lucile Lallemant, Gilbert Fantozzi, Méthodes et outils pour l'Interaction à gestes (MINT2), 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-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Inria Lille - Nord Europe, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Matériaux, ingénierie et science [Villeurbanne] (MATEIS), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), 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 interuniversitaire de recherche et d'ingenierie des matériaux (CIRIMAT), Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Laboratoire de Physique et Mécanique Textiles (LPMT), ENSITM-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Baikowski (FRANCE), Centro de Innovación, Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT), Universidad Nacional Autónoma de México (UNAM), 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), Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Centrale Lille-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), 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), Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Méthodes et outils pour l'Interaction à gestes ( MINT2 ), 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 (CRIStAL) - UMR 9189 ( CRIStAL ), Institut National de Recherche en Informatique et en Automatique ( Inria ) -Ecole Centrale de Lille-Institut Mines-Télécom [Paris]-Université de Lille-Centre National de la Recherche Scientifique ( CNRS ) -Ecole Centrale de Lille-Institut Mines-Télécom [Paris]-Université de Lille-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 ), Centre interuniversitaire de recherche et d'ingenierie des matériaux ( CIRIMAT ), Institut National Polytechnique [Toulouse] ( INP ) -Université Paul Sabatier - Toulouse 3 ( UPS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique et Mécanique Textiles ( LPMT ), Université de Haute-Alsace (UHA) Mulhouse - Colmar ( Université de Haute-Alsace (UHA) ) -ENSITM-Matériaux et nanosciences d'Alsace, Université de Strasbourg ( UNISTRA ) -Université de Haute-Alsace (UHA) Mulhouse - Colmar ( Université de Haute-Alsace (UHA) ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Strasbourg ( UNISTRA ) -Institut National de la Santé et de la Recherche Médicale ( INSERM ) -Centre National de la Recherche Scientifique ( CNRS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), and Universidad Autonoma de Nuevo Leon [Mexique] (UANL)

Subjects
010302 applied physics, Materials science, Fabrication, Dopant, [ SPI.MAT ] Engineering Sciences [physics]/Materials, Nanoparticle, Sintering, 02 engineering and technology, Large range, 021001 nanoscience & nanotechnology, 01 natural sciences, Grain size, [SPI.MAT]Engineering Sciences [physics]/Materials, visual_art, 0103 physical sciences, Materials Chemistry, Ceramics and Composites, visual_art.visual_art_medium, Ceramic, Composite material, 0210 nano-technology
Abstract

International audience; Using discrete, ultrafine alumina, highly dense transparent (71% real in-line transmission, RIT, =640nm) ceramics were achieved with grain size as small as 260nm using standard SPS sintering. We show that use of La3+ as a dopant greatly reduces sensitivity to the sintering temperatures. Transparent alumina were achieved in a large range of sintering temperatures, 1140 degrees C

Published
2013

11. Discussion on the interpretation of the effective wavenumber for coherent multiple scattering problem

Author

Loïc Le Marrec, Grégory Futhazar, Mathieu Chekroun, Bruno Lombard, Joel Piraux, Institut de Recherche Mathématique de Rennes ( IRMAR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -AGROCAMPUS OUEST-École normale supérieure - Rennes ( ENS Rennes ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National des Sciences Appliquées ( INSA ) -Université de Rennes 2 ( UR2 ), Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'acoustique de l'université du Mans ( LAUM ), Le Mans Université ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Institut de Recherche Mathématique de Rennes (IRMAR), AGROCAMPUS OUEST, 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)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-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), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Centre National de la Recherche Scientifique (CNRS)-Le Mans Université (UM), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Lombard, Bruno, Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École normale supérieure - Rennes (ENS Rennes)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-INSTITUT AGRO Agrocampus Ouest, 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), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

12. Multiple scattering of elastic waves: a time-domain numerical method to compute the effective wavenumbers

Author

Mathieu Chekroun, Loïc Le Marrec, Bruno Lombard, Joel Piraux, Lombard, Bruno, Laboratoire d'acoustique de l'université du Mans ( LAUM ), Le Mans Université ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherche Mathématique de Rennes ( IRMAR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -AGROCAMPUS OUEST-École normale supérieure - Rennes ( ENS Rennes ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National des Sciences Appliquées ( INSA ) -Université de Rennes 2 ( UR2 ), Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Centre National de la Recherche Scientifique (CNRS)-Le Mans Université (UM), Institut de Recherche Mathématique de Rennes (IRMAR), AGROCAMPUS OUEST, 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)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-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), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École normale supérieure - Rennes (ENS Rennes)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-INSTITUT AGRO Agrocampus Ouest, 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), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

13. Numerical simulation of multiple scattering in concrete

Author

Mathieu Chekroun, Loïc Le Marrec, Bruno Lombard, Joel Piraux, Laboratoire d'acoustique de l'université du Mans ( LAUM ), Le Mans Université ( UM ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherche Mathématique de Rennes ( IRMAR ), Université de Rennes 1 ( UR1 ), Université de Rennes ( UNIV-RENNES ) -Université de Rennes ( UNIV-RENNES ) -AGROCAMPUS OUEST-École normale supérieure - Rennes ( ENS Rennes ) -Institut National de Recherche en Informatique et en Automatique ( Inria ) -Institut National des Sciences Appliquées ( INSA ) -Université de Rennes 2 ( UR2 ), Université de Rennes ( UNIV-RENNES ) -Centre National de la Recherche Scientifique ( CNRS ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Mathématique de Rennes (IRMAR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École normale supérieure - Rennes (ENS Rennes)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-INSTITUT AGRO Agrocampus Ouest, 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), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Le Mans Université (UM), AGROCAMPUS OUEST, 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)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-École normale supérieure - Rennes (ENS Rennes)-Centre National de la Recherche Scientifique (CNRS)-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)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Lombard, Bruno

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [ SPI.ACOU ] Engineering Sciences [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

14. Modelling of ultrasound transmission through a solid-liquid interface comprising a network of gas pockets

Author

Gilles Corneloup, Francois Baque, Dominique Chatain, Joseph Moysan, Kevin Paumel, Service de Technologie des Composants et des Procédés (STCP), Département Technologie Nucléaire (DTN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Caractérisation Non Destructive [Aix en Provence] (LCND), MISTRAL-Lab, CEA Cadarache, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre de recherche de la matière condensée et des nanosciences (CRMCN), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ), Ondes et Imagerie ( O&I ), Laboratoire de Mécanique et d'Acoustique [Marseille] ( LMA ), Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ) -Aix Marseille Université ( AMU ) -Ecole Centrale de Marseille ( ECM ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de recherche de la matière condensée et des nanosciences ( CRMCN ), Université de la Méditerranée - Aix-Marseille 2-Université Paul Cézanne - Aix-Marseille 3-Centre National de la Recherche Scientifique ( CNRS ), and Département Technologie Nucléaire ( DTN )

Subjects
Materials science, Analytical chemistry, General Physics and Astronomy, 02 engineering and technology, Surface finish, ultrasounds, 01 natural sciences, Nondestructive testing, 0103 physical sciences, Surface roughness, sodium fast reactor, Transmission coefficient, Composite material, 010301 acoustics, [ PHYS.MECA.ACOU ] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], non destructive testing, wetting, business.industry, Ultrasonic testing, technology, industry, and agriculture, 021001 nanoscience & nanotechnology, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Transducer, Computer Science::Graphics, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], interface, Ultrasonic sensor, spring model, Wetting, 0210 nano-technology, business
Abstract

International audience; Ultrasonic inspection of sodium-cooled fast reactor requires a good acoustic coupling between the transducer and the liquid sodium. Ultrasonic transmission through a solid surface in contact with liquid sodium can be complex due to the presence of microscopic gas pockets entrapped by the surface roughness. Experiments are run using substrates with controlled roughness consisting of a network of holes and a modeling approach is then developed. In this model, a gas pocket stiffness at a partially solid-liquid interface is defined. This stiffness is then used to calculate the transmission coefficient of ultrasound at the entire interface. The gas pocket stiffness has a static, as well as an inertial component, which depends on the ultrasonic frequency and the radiative mass.

Published
2011

15. SYSTÈME EXPÉRIMENTAL ET OUTILS NUMÉRIQUES POUR LE DÉVELOPPEMENT D'UNE THÉRAPIE PHOTOTHERMIQUE POUR LE TRAITEMENT DES GLIOBLASTOMES

Author

Capart, Antoine, Metwally, Khaled, Bastiancich, Chiara, da Silva, Anabela, DiMABio (DiMABio), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Institut de neurophysiopathologie (INP), and Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics]
Abstract

International audience

Published
2022

16. Fractal Analysis of a Non-Newtonian Fluid Flow in a Rough-Walled Pipe

Author

Abdellah Bouchendouka, Zine El Abiddine Fellah, Zakaria Larbi, Zineeddine Louna, Erick Ogam, Mohamed Fellah, Claude Depollier, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Acoustique de l'Université du Mans (LAUM), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Condensed Matter::Soft Condensed Matter, Physics::Fluid Dynamics, rough surface, fractal surface, surface fractal dimensions, non-Newtonian fluids, General Materials Science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph]
Abstract

International audience; The fully developed laminar flow of a viscous non-Newtonian fluid in a rough-walled pipe is considered. The fluid rheology is described by the power–law model (covering shear thinning, Newtonian, and shear thickening fluids). The rough surface of the pipe is considered to be fractal, and the surface roughness is measured using surface fractal dimensions. The main focus of this study lies in the theoretical investigation of the influence of the pipe surface roughness on the velocity profile and the Darcy friction factor of an incompressible non-Newtonian fluid. The plotted results demonstrate that shear thinning fluids are the most sensitive to the surface roughness compared with Newtonian and shear thickening fluids. For a particular value of the surface fractal dimension, there exists an intersection point where shear thinning, Newtonian, and shear thickening fluids behave the same way regarding the amplitude of the velocity profile and the friction factor. This approach has a variety of potential applications, for instance fluid dynamics in hydrology, blood flow in the cardiovascular system, and many industrial applications

Published
2022
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17. Temperature-Dependent Elastic Constants of Substrates for Manufacture of Mems Devices

Author

Ongwen, Nicholas O., Ogam, Erick, Otunga, Henry, Fellah, Zine El Abiddine, Oduor, Andrew, Mageto, Maxwell, 1Maseno University, P. O. Box Private Bag, Maseno, 40137, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Materials Science, Maseno University, Maseno, Kenya, and Masinde Muliro University of Science and Technology [Kakamega, Kenya]

Subjects
[PHYS]Physics [physics], [SPI]Engineering Sciences [physics]
Abstract

International audience; We present a comparative computational study of temperature-dependent elastic constants of silicon (Si), silicon carbide (SiC) and diamond as substrates that are commonly used in the manufacture of Micro-Electromechanical Systems (MEMS) devices. Also mentioned is Cd 2 SnO 4 , whose ground-state elastic constants were determined just recently for the first time. Si is the dominant substrate used in the manufacture of MEMS devices, owing to its desirable electrical, electronic, thermal and mechanical properties. However, its low hardness, brittleness and inability to work under harsh environment such as hightemperature environment, has limited its use in the manufacture of MEMS like mechanical sensors and bioMEMS. Mechanical sensors are fabricated on SiC and diamond due to their high Young's moduli as well as high fracture strength, while the bioMEMS are fabricated on polymers. The effect of temperature on the elastic constants of these substrates will help in giving insight into how their performance vary with temperature.

Published
2022

18. Addressing the ill-posedness of multi-layer porous media characterization in impedance tubes through the addition of air gaps behind the sample: numerical validation

Author

Zine El Abiddine Fellah, Erick Ogam, Rémi Roncen, ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Fellah, Zine El Abiddine

Subjects
Materials science, Acoustics and Ultrasonics, Bayesian inference, 01 natural sciences, Standard deviation, Synthetic data, air gaps, 0103 physical sciences, Porosity, 010301 acoustics, Electrical impedance, 010302 applied physics, Mechanical Engineering, Isotropy, multi-layer materials, Mechanics, material characterization, Inverse problem, Condensed Matter Physics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], impedance tube, Mechanics of Materials, Porous medium, Focus (optics), [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], porous materials
Abstract

International audience; This paper is concerned with plane wave propagation in multi-layer assemblies of rigid isotropic porous media inside impedance tubes. The focus is placed on the inverse problem, i.e., the retrieval of the intrinsic properties defining the pore micro-structure of each layer: the porosity, the pore mean size and the pore size standard deviation. Each layer is considered isotropic. Such an inverse problem can be ill-posed due to the non-uniqueness of the solution. The technique explored in this work is the consideration of additional acoustic observations, where air gaps are placed behind the multi-layer assembly. The aptitude of this strategy to overcome the ill-posedness of the inverse problem is evaluated on numerical synthetic data, on assemblies made of three layers. For a given fixed amount of input data, inverse problems including different observations with air gaps can yield more accurate results, removing the ill-posedness.

Published
2022

19. Analysis of the Acoustic Transcranial Bone Conduction

Author

Catherine Dufour-Fournier, Arnaud Devèze, Jonathan Barbut, Erick Ogam, Issam Saliba, Catherine Masson, Department of Otolaryngology and Head and Neck Surgery, University of Montreal, Montreal, Université du Québec à Montréal = University of Québec in Montréal (UQAM), Department of Otology and Skull Base Surgery, Ramsay Health Care, Clairval Hospital, 317 Bd du Redon, 13009 Marseille, France, Clairval Hospital, Laboratoire de Biomécanique Appliquée (LBA UMR T24), Aix Marseille Université (AMU)-Université Gustave Eiffel, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche du Centre Hospitalier de l’Université de Montréal (CR CHUM), Centre Hospitalier de l'Université de Montréal (CHUM), and Université de Montréal (UdeM)-Université de Montréal (UdeM)

Subjects
otology, acoustic, bone conduction, BAHA, Otorhinolaryngology, sound transmission, otorhinolaryngologic diseases, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Objectives: (1) To analyze the preferential pathways of sound transmission and sound waves travelling properties in the skull and (2) to identify the location(s) on the skull where bone conduction to the cochlea is optimal. Study design: Basic research Methods: Nine cadaveric heads were placed in an anechoic chamber and equipped with six Bone Anchored Hearing Aids (BAHA™) implants (Cochlear™, Sydney, NSW, Australia) and fifteen accelerometers. A laser velocimeter was used to measure cochlear response by placing a reflector on the round window. Different frequency sweeps were applied to each implant, and measurements were recorded simultaneously by the laser velocimeter and accelerometers. Results: Low-frequency sound waves mostly travel the frontal transmission pathways, and there is no clear predominant pattern for the high frequencies. The mean inter-aural time lag is 0.1 ms. Optimal sound transmission to the cochlea occurs between 1000 and 2500 Hz with a contralateral 5 to 10 dB attenuation. The implant location does not influence mean transmission to the cochlea. Conclusion: There is a pattern of transmission for low frequencies through a frontal pathway but none for high frequencies. We were also able to demonstrate that the localization of the BAHA™ implant on the skull had no significant impact on the sound transmission, either ipsi or contralaterally.

Published
2022

20. Numerical and Experimental Study of Wave Propagation in Water-Saturated Granular Media Using Effective Method Theories and a Full-Wave Numerical Simulation

Author

Paul Cristini, Dimitri Komatitsch, Yann Capdeville, Katsunori Mizuno, University of Tokyo, Graduate School of Frontier Sciences, The University of Tokyo (UTokyo), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ANR-16-CE31-0022,HIWAI,Inversion homogénéisée de formes d'ondes sismiques(2016), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
010302 applied physics, Physics, time-domain full-wave numerical method, Computer simulation, Biot-Stoll model, 010505 oceanography, Wave propagation, Mechanical Engineering, Numerical analysis, Ocean Engineering, Mechanics, water-saturated granular media, 01 natural sciences, Homogenization (chemistry), Grain size, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Wavelength, 0103 physical sciences, Effective method, 14. Life underwater, Electrical and Electronic Engineering, Anisotropy, nonperiodic homogenization, 0105 earth and related environmental sciences
Abstract

International audience; In this article, the detection of an object buried in marine sediments is investigated. Using the results from a series of experiments realized in a tank filled with water and calibrated glass beads, we evaluate the performances for a wide range of the value of the ratio kd of the grain size to the wavelength (k is the wave number and d is the grain diameter) of three types of prediction tools. The first two prediction tools are based on the definition of an equivalent model. The first tool is based on the well-known Biot-Stoll theory (BM model) while the second tool uses nonperiodic homogenization to define effective velocity and anisotropy maps representing the medium (HM model). The last prediction tool implements a time-domain full-wave numerical method, which takes into account each grain separately (GM model). It is shown that a good agreement between experiments and numerical simulations can be achieved using the BM model for the low kd regime and the HM model for high kd regime.

Published
2020

21. Transient Propagation of Spherical Waves in Porous Material: Application of Fractional Calculus

Author

Zine El Abiddine Fellah, Mohamed Fellah, Rémi Roncen, Nicholas O. Ongwen, Erick Ogam, Claude Depollier, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT), Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Department of Physics and Materials Science, Maseno University, Maseno, Kenya., Laboratoire d'Acoustique de l'Université du Mans (LAUM), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
porous materials, fractional calculus, spherical wave, viscous and thermal surfaces, dynamic tortuosity and compressibility, Physics and Astronomy (miscellaneous), Chemistry (miscellaneous), General Mathematics, Computer Science (miscellaneous), Transient Propagation of porous materials, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; A fractional-order wave equation is established and solved for a space of three dimensions using spherical coordinates. An equivalent fluid model is used in which the acoustic wave propagates only in the fluid saturating the porous medium; this model is a special case of Biot’s theory obtainedby the symmetry of the Lagrangian (invariance by translation and rotation). The basic solution of the wave equation is obtained in the time domain by analytically calculating Green’s function of the porous medium and using the properties of the Laplace transforms. Fractional derivatives are used to describe, in the time domain, the fluid–structure interactions, which are of the inertial, viscous, and thermal kind. The solution to the fractional-order wave equation represents the radiation field in the porous medium emitted by a point source. An important result obtained in this study is that the solution of the fractional equation is expressed by recurrence relations that are the consequence of the modified Bessel function of the third kind, which represents a physical solution of the wave equation. This theoretical work with analytical results opens up prospects for the resolution of forward and inverse problems allowing the characterization of a porous medium using spherical waves.

Published
2022

22. Influence of Higher Order Viscous and Thermal Effects on an Ultrasonic Wave Reflected from the First Interface of a Porous Material

Author

Zine El Abiddine Fellah, Rémi Roncen, Nicholas O. Ongwen, Erick Ogam, Mohamed Fellah, Claude Depollier, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Department of Physics and Materials Science, Maseno University, Maseno, Kenya., Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT), Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Laboratoire d'Acoustique de l'Université du Mans (LAUM), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Technology, Microscopy, QC120-168.85, First Interface, Dynamic Tortuosity and Compressibility, QH201-278.5, Porous Materials, Engineering (General). Civil engineering (General), Viscous and Thermal Surfaces, TK1-9971, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Descriptive and experimental mechanics, Reflected Wave, porous materials, reflected wave, first interface, viscous and thermal surfaces, dynamic tortuosity and compressibility, General Materials Science, Electrical engineering. Electronics. Nuclear engineering, TA1-2040
Abstract

International audience; Ultrasound propagation in porous materials involves some higher order physical parameters whose importance depends on the acoustic characteristics of the materials. This article concerns the study of the influence of two parameters recently introduced, namely, the viscous and thermal surfaces, on the acoustic wave reflected by the first interface of a porous material with a rigid structure. These two parameters describe the fluid/structure interactions in a porous medium during the propagation of the acoustic wave in the high-frequency regime. Both viscous and thermal surfaces are involved in Laurent expansion, which is limited to the dynamic tortuosity and compressibility to a higher order and corrects the visco-thermal losses %Please check intended meaning has been retained. A sensitivity study is performed on the modulus of the reflection coefficient at the first interface as a function of frequency and on the waveforms reflected by the porous material in the time domain. The results of this study show that absorbent porous materials are the most sensitive to viscous and thermal surfaces, which makes the consideration of these two parameters paramount for the characterization of highly absorbent porous materials using the waves reflected from the first interface.

Published
2022
Full Text
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23. Effects of Polydispersity and High Scatterer Concentration on Quantitative Ultrasound Estimates

Author

Olivier Lombard, Mylena Audenay, Emilie Franceschini, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université d'Avignon, UMR EMMAH, Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH), Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Franceschini, Emilie

Subjects
Backscatter, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [SDV.IB.IMA] Life Sciences [q-bio]/Bioengineering/Imaging, [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, polydisperse, scattering, microstructure, scatterer size
Abstract

International audience; Quantitative ultrasound (QUS) techniques for the estimation of tissue microstructures are based on the frequency analysis of backscattered signals from the tissue. One of these QUS methods relies on theoretical scattering models that match a theoretical backscatter coefficient (BSC) to the measured BSC in order to estimate QUS parameters (such as the effective scatterer size and acoustic concentration). The scattering models generally assume that the tissue under consideration contains identical scatterers in sparse medium and may provide QUS parameters that are not representative of the actual tissue microstructure when the medium is polydisperse in scatterer size and/or dense. Our goal is to study the effects of scatterer polydispersity on QUS estimates by considering three scattering models: the monodisperse sparse model, the polydisperse sparse model and the monodisperse concentrated structure factor model (SFM). In that aim, simulations of backscatter coefficients are conducted with different scatter size distributions for sparse or moderately dense media. The QUS parameters are estimated at different center frequencies f0 (from 10 MHz up to 50 MHz) by fitting the simulated backscatter coefficient in the frequency bandwidth [0.5f0 − 1.5f0], i.e. assuming a transducer with 100% usable bandwidth. The choice of scattering models have a high impact on the QUS parameter estimates as function of frequencies for values of ka less than 1.2.

Published
2022

24. Investigation of long acoustic waveguides for the very low frequency characterization of monolayer and stratified air-saturated poroelastic materials

Author

Erick Ogam, Zine El Abiddine Fellah, Andrew O. Oduor, Géry Ogam, Nicholas O. Ongwen, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Independent Consultant, Department of Physics and Materials Science, Maseno University, Maseno, Kenya., and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, low-frequency characterization, Materials science, Acoustics and Ultrasonics, open-cell plastic foams, Acoustics, Poromechanics, Transfer-matrix method (optics), Stratied layers, Acoustic wave, 01 natural sciences, Tortuosity, Cutoff frequency, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], transfer matrix method, 0103 physical sciences, Air-saturated poroelastic, Waveguide (acoustics), Acoustic waveguide, Transmission coefficient, Porous medium, 010301 acoustics
Abstract

When sound propagates in a porous medium, it is attenuated via several energy loss mechanisms which are switched on or off as the excitation frequency varies. The classical way of measuring acoustic energy loss in porous materials uses the Kundt impedance tube. However, due to its short length, measurements are made in the steady state harmonic regimes. Its lower cutoff frequency is often limited to a few hundreds of Hertz. Two long acoustic waveguides were assembled from water pipes and mounted to create test-rigs for the low-frequency acoustic characterization of monolayer and stratified air-saturated poroelastic materials. The first waveguide was straight and had a length of 120 m, while the second was coiled to gain space and was 135 m long. The long waveguides appeal to very low frequency measurements using impulsive acoustic waves (with rich spectral content) because the incident waves can be separated in time from echoes off the extremities of the guides. The transmission coefficient of porous materials recovered using the two waveguides compared well with those from the transfer matrix method (TMM) used here in combination with Biot’s 1962 theory to describe propagation in porous dissipative media. This wave-material interaction model permitted the recovery of the properties of poroelastic materials from transmitted acoustic waves propagating in air. The parameters involved are the Young’s moduli, Poisson ratio and microstructural properties such as tortuosity and permeability. Being able to descend to lower frequencies guarantees the correct verification of the magnitude of the measured transmission coefficient which approaches unity towards the static frequency. The coiled and straight waveguides were found to be equivalent and provided data down to frequencies of the order of ≈ 12 Hz.

Published
2021

25. Theoretical and experimental study of micropolar elastic materials using acoustic waves in air

Author

Zine El Abbidine Fellah, Mohamed Fellah, Claude Depollier, Erick Ogam, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT), Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Centre National de la Recherche Scientifique (CNRS)-Le Mans Université (UM), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), and Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Acoustics and Ultrasonics, Frequency band, Mechanical Engineering, Acoustics, 02 engineering and technology, Acoustic wave, 021001 nanoscience & nanotechnology, Condensed Matter Physics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Transverse plane, 020303 mechanical engineering & transports, Transducer, 0203 mechanical engineering, Mechanics of Materials, Ultrasonic sensor, Loudspeaker, Phase velocity, 0210 nano-technology, Reduction (mathematics), ComputingMilieux_MISCELLANEOUS
Abstract

This study focuses on the development of a theoretical and experimental acoustic method and setup for studying the micropolar behavior of materials. Two types of low density closed-cell foams made from polystyrene (expanded and extruded) materials that were previously reported as materials exhibiting the non-classical elastodynamic behavior were investigated in order to reveal the particular comportment using acoustic waves. Two different types of transducers were employed to provide a large frequency band to study the influence of the Cosserat parameters. The frequency band from 1–40 kHz was covered using a tweeter loudspeaker whereas that from 30–120 kHz, by an air coupled ultrasonic transducer. The materials’ micropolar elastic behavior were revealed through the comparison between the theoretical and experimental transmission coefficients. At the cut-off frequency where the theoretical phase velocity of the transverse acoustic mode was established to be infinite, the acoustic wave transmission by the panels was found to be very small. This makes the Cosserat materials appealing to harmonic noise reduction.

Published
2021

26. Vibration monitoring of nuclear power plant containment buildings during the Integrated Leakage Rate Test for structural condition assessment

Author

J. N. Eiras, Cédric Payan, Agustin Spalvier, Vincent Garnier, Sandrine T. Rakotonarivo, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Nuclear engineering, Leakage rate, 01 natural sciences, law.invention, Vibration, [SPI]Engineering Sciences [physics], Containment, Mechanics of Materials, law, Structural condition, 0103 physical sciences, Nuclear power plant, Environmental science, Safety, Risk, Reliability and Quality, 010301 acoustics, Civil and Structural Engineering
Abstract

This study investigates the use of the operational vibrations produced during the Integrated Leak Rate Test of nuclear power plant containment buildings for further informing on its mechanical condition. The experiment is performed on a 1:3-scale containment building mock-up. The results show that meaningful vibrations were generated during the pressurization test. Different features were extracted from the vibration signals and analyzed as a function of the internal pressure. Experimental modal analysis was performed and demonstrated that several frequency peaks generated during the pressurization cycle effectively corresponded to the eigenmodes of the containment building. The identified operational frequency modes exhibited remarkable hysteretic dependencies on the internal pressure. The latter was phenomenologically described through a simplified two-dimensional (2D) finite element model of the vessel. Besides, a surrogate statistical model based on the Principal Component Analysis of the vibration data was proposed as a baseline and so detect abnormal behavior. Then, different synthetic damage scenarios were created by subtlety altering the recorded signals and ultimately substantiate the capability of the statistical model to detect these odd signals. Finally, conclusions were drawn regarding the possibility of using mechanical vibrations for assisting in the licensing process of nuclear power plants and monitor the structural health condition of in-service containment buildings.

Published
2021

27. Corrigendum on 'Microstructural and elastic properties of stable aluminium-rich TiAl and TiAl2 formed phase intermetallics' [Mater. Lett. 287 (2021) 129295]

Author

Andrew O. Oduor, Nicholas O. Ongwen, Erick Ogam, Daoud Chanbi, Zine El Abiddine Fellah, Henry Otunga, Department of Physics and Materials Science, Maseno University, Maseno, Kenya, University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, 010405 organic chemistry, Mechanical Engineering, Intermetallic, chemistry.chemical_element, 010402 general chemistry, Condensed Matter Physics, 01 natural sciences, 0104 chemical sciences, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], chemistry, Mechanics of Materials, Aluminium, Phase (matter), General Materials Science, Composite material, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2021

28. Transient Propagation of Longitudinal and Transverse Waves in Cancellous Bone: Application of Biot Theory and Fractional Calculus

Author

Djihane Benmorsli, Zine El Abiddine Fellah, Djema Belgroune, Nicholas O. Ongwen, Erick Ogam, Claude Depollier, Mohamed Fellah, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Materials Science, Maseno University, Maseno, Kenya, Laboratoire d'Acoustique de l'Université du Mans (LAUM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), and Laboratoire de Physique Théorique [University of Science and Technology Houari Boumediene] (LPT)

Subjects
Biot theory, porous materials, fractional calculus, transverse wave, transmission, Physics and Astronomy (miscellaneous), Chemistry (miscellaneous), General Mathematics, Computer Science (miscellaneous), [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; In this paper, the influence of the transverse wave on sound propagation in a porous medium with a flexible structure is considered. The study is carried out in the time domain using the modified Biot theory obtained by the symmetry of the Lagrangian (invariance by translation and rotation). The viscous exchanges between the fluid and the structure are described by fractional calculus. When a sound pulse arrives at normal incidence on a porous material with a flexible structure, the transverse waves interfere with the longitudinal waves during propagation because of the viscous interactions that appear between the fluid and the structure. By performing a calculation in the Laplace domain, the reflection and transmission operators are derived. Their time domain expressions depend on the Green functions of the longitudinal and transverse waves. In order to study the effects of the transverse wave on the transmitted longitudinal waves, numerical simulations of the transmitted waves in the time domain by varying the characteristic parameters of the medium are realized whether the transverse wave is considered or not.

Published
2022

29. Acoustical characterisation and monitoring of microbubble clouds

Author

Serge Mensah, Lilian D'Hondt, Cédric Payan, Matthieu Cavaro, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Service de Technologie des Composants et des Procédés (STCP), Département Technologie Nucléaire (DTN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), MISTRAL-Lab, Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, education.field_of_study, Materials science, Acoustics and Ultrasonics, Opacity, Bubble, Population, Mechanics, 01 natural sciences, Integral equation, Physics::Fluid Dynamics, [SPI]Engineering Sciences [physics], Cavitation, Boiling, 0103 physical sciences, Microbubbles, Wavenumber, education, 010301 acoustics
Abstract

International audience; Argon microbubbles will exist in the primary sodium of the next generation of sodium-cooled fast reactors (SFR). Due to its opacity, acoustic methods will be used for the in-service inspection in these reactors, but the presence of such bubbles will greatly affect ultrasonic wave propagation. Moreover, these bubbles can lead to the formation of gas pockets in the reactor and impact cavitation and boiling phenomena. It is therefore necessary to characterise what is called the 'microbubble cloud' by providing the volume fraction and the bubble size distribution. Safety requirements in this field call for robust inspection methods based on very few assumptions about the bubble populations. The objective of this study is to assess the performance of spectroscopic methods in the presence of bubbles with high polydispersity and to monitor an evolving cloud of microbubbles. The histogram and void fractions were estimated according to the regularised inversion of the complex wave number's integral equation. To reduce the need for prior information on the bubble cloud, a specific procedure was used to estimate the maximum radius of the population. The results are presented on the basis of the experimental data obtained and then compared with optical measurements.

Published
2019

30. Passive structural monitoring based on data-driven matched field processing

Author

François Baqué, Sandrine T. Rakotonarivo, J.-F. Chaix, William A. Kuperman, Serge Mensah, Emma Lubeigt, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Service de Technologie des Composants et des Procédés (STCP), Département Technologie Nucléaire (DTN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Marine Physical Laboratory (MPL), Scripps Institution of Oceanography (SIO - UC San Diego), University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC)-University of California [San Diego] (UC San Diego), University of California (UC)-University of California (UC), MISTRAL-Lab, Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Scripps Institution of Oceanography (SIO), University of California-University of California-University of California [San Diego] (UC San Diego), and University of California-University of California

Subjects
Acoustics and Ultrasonics, Field (physics), 010505 oceanography, Computer science, Acoustics, Ambient noise level, Condition monitoring, White noise, 01 natural sciences, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Vibration, Minimum-variance unbiased estimator, Arts and Humanities (miscellaneous), Frequency domain, 0103 physical sciences, 010301 acoustics, Structural acoustics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

A passive data-driven method to localize a defect in a structure using the ambient noise is derived. The approach requires only acoustic measurements in a spatially random noise field and no knowledge of the structure. Measurements are taken before and after the perturbation has occurred and Green's functions are retrieved by cross-correlating acoustic measurements. The difference between measured data reveals the perturbation. A frequency domain method based on matched field processing is then performed to localize the perturbation. The Bartlett, minimum variance and white noise gain constraint processors are implemented and their performances are illustrated on a numerical experiment.

Published
2019

31. Ultrasonic Imaging of High-contrasted Objects Based on Full-waveform Inversion: Limits under Fluid Modeling

Author

Luis Espinosa, Vadim Monteiller, Simon Bernard, Elise Doveri, Régine Guillermin, Philippe Lasaygues, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Ondes et Milieux Complexes (LOMC), Centre National de la Recherche Scientifique (CNRS)-Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU), Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Institut Clément Ader (ICA), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO)-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)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-IMT École nationale supérieure des Mines d'Albi-Carmaux (IMT Mines Albi), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Shear waves, Radiological and Ultrasound Technology, Computer science, Acoustics, Attenuation, Experimental data, Inversion (meteorology), Inverse problem, 010502 geochemistry & geophysics, 01 natural sciences, Viscoelasticity, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 030218 nuclear medicine & medical imaging, 03 medical and health sciences, [SPI]Engineering Sciences [physics], Sound, 0302 clinical medicine, Speed of sound, Radiology, Nuclear Medicine and imaging, Acoustic impedance, Algorithms, Ultrasonography, 0105 earth and related environmental sciences
Abstract

International audience; Quantitative ultrasound techniques have been previously used to evaluate biological hard tissues, characterized by a large acoustic impedance contrast. Here, we are interested in the imaging of experimental data from different test-targets with high acoustic impedance contrast, using the Full Waveform Inversion (FWI) method to solve the inverse problem. This method is based on high-resolution numerical modeling of the forward problem of interaction between waves and medium, considering the full time series. To reduce the complexity of the numerical implementation, the model considers a fluid medium. Therefore, the aim is to evaluate the precision of the reconstruction under this assumption for materials with a different level of attenuation of shear waves, to study the limits of this hypothesis. Images of the sound speed obtained using the experimental data are presented, and the precision of the reconstruction is evaluated. Future work should include viscoelastic materials.

Published
2021

32. Fracture processes imaging in concrete using nonlinear ultrasound

Author

Marcel C. Remillieux, Timothy J. Ulrich, Pierre Yves Le Bas, Vincent Garnier, Martin Lott, Arnaud Deraemaeker, Cédric Payan, Cédric Dumoulin, Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Grenoble Alpes (UGA)-Université Gustave Eiffel-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Los Alamos National Laboratory (LANL), Université Libre de Bruxelles, BATir Department, Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Cracks, Micro damage, Mechanical Engineering, Acoustics, Micro cracks, Fracture process zone, Sciences de l'ingénieur, Condensed Matter Physics, 01 natural sciences, Characterization (materials science), Nonlinear ultrasound, Nonlinear system, [SPI]Engineering Sciences [physics], Nonlinear parameters, 0103 physical sciences, Fracture (geology), High harmonic generation, General Materials Science, 010306 general physics, 010301 acoustics, Concrete
Abstract

International audience; This paper shows the complementarity of two nonlinear ultrasonic imaging methods to characterize closed macro cracks in concrete. A time reversal mirror is used to locally probe and image the nonlinearity of a cracked region. Two nonlinear parameters are extracted to map the cracked region. The image obtained using the first parameter relates the harmonic generation due to the contact and frictional behaviors at the crack lips, correlated with vibro-thermography imaging of the same crack. The image obtained using the second parameter is based on the conditioning of the material induced by distributed micro cracks arising from the fracture process zone. These results show a great potential for characterization of fracture processes in concrete, with the possibility to uncouple the effects of the crack itself from surrounding distributed micro damage.

Published
2021

33. Structural and Mechanical Properties of theTi32Al68 and Ti40Al60 Binary Alloys: Experimental and computational Studies

Author

Ongwen, Nicholas, Chanbi, Daoud, Erick, Ogam, Otunga, Henry, Oduor, Andrew, Fellah , Zine El Abiddine, Department of Physics and Materials Science, Maseno University, Maseno, Kenya., Laboratoire d’Electrochimie, Corrosion, Métallurgie et Chimie Minérale, Université des Sciences et de la technologie de Houari Boumediene, Algeria, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Materials Science, Maseno University, Maseno, Kenya, and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
ComputingMilieux_MISCELLANEOUS, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience

Published
2021

34. Propagation acoustique dans un milieu poreux : effet de l'onde de cisaillement

Author

Benmorsli, Djihane, Fellah, Zine El Abiddine, Belgroune, Djemaa, Ogam, Erick, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Milieux poreux, Opérateurs de réflexion et de transmission, Théorie de Biot, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; L'étude de la propagation d'une onde sonore sur une tranche de matériau poreux à structure souple est étudiée dans le domaine temporel. Le calcul fractionnaire est utilisé dans le cadre de la théorie de Biot. L'onde de cisaillement est décrite pour une incidence normale, en plus des ondes longitudinales. Les interactions fluide/structure de nature visqueuse sont prises en compte via des opérateurs temporels. Le calcul analytique des opérateurs de réflexion et de transmission est effectué dans le domaine temporel. Une étude de sensibilité des paramètres physiques caractérisant le milieu est donnée par simulation numériques d'ondes transmises.

Published
2021

35. Numerical investigations of anisotropic structures of red blood cell aggregates on ultrasonic backscattering

Author

Curtis Armstrong, Rym Mehri, Marianne Fenech, Emilie Franceschini, Lenin Chinchilla, Alessandro Stuart Savoia, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Université d'Ottawa [Ontario] (uOttawa), Università degli Studi Roma Tre, Chinchilla, L., Armstrong, C., Mehri, R., Savoia, A. S., Fenech, M., Franceschini, E., Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Università degli Studi Roma Tre = Roma Tre University (ROMA TRE)

Subjects
Rouleaux, [SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Materials science, Erythrocytes, Acoustics and Ultrasonics, Scattering, Orientation (computer vision), [SDV.IB.IMA]Life Sciences [q-bio]/Bioengineering/Imaging, [PHYS.PHYS.PHYS-BIO-PH]Physics [physics]/Physics [physics]/Biological Physics [physics.bio-ph], Isotropy, Aggregate (data warehouse), Physics::Medical Physics, Inverse problem, 01 natural sciences, Characterization (materials science), Computational physics, Arts and Humanities (miscellaneous), 0103 physical sciences, Anisotropy, Computer Simulation, Ultrasonics, 010306 general physics, 010301 acoustics, Ultrasonography
Abstract

International audience; Although quantitative ultrasound techniques based on the parameterization of the backscatter coefficient (BSC) have been successfully applied to blood characterization, theoretical scattering models assume blood as an isotropic scattering medium. However, the red blood cell (RBC) aggregates form anisotropic structures such as rouleaux in healthy blood. Therefore, the present study aims to progress further in the understanding of ultrasonic scattering from anisotropic RBC aggregates. Computer simulations were performed to compute the frequency-dependent BSC for different aggregating configurations: polydisperse spherical aggregates, randomly oriented or perfectly aligned prolate-shaped aggregates, and complex configurations with partially aligned prolate-shaped aggregates. Two scattering models were examined: the isotropic effective medium theory combined with the local monodisperse approximation (EMTLMA) and the anisotropic formulation of the EMTLMA considering perfectly aligned structures. When considering aligned prolate-shaped aggregates, the anisotropic EMTLMA was found to be superior to the isotropic EMTLMA in estimating the scatterer volume distribution. When considering the complex aggregating configurations, both isotropic and anisotropic EMTLMA yielded similar scatterer volume distribution. The mean scatterer size was underestimated when considering randomly oriented prolate-shaped aggregates and complex configurations with partially aligned structures. These results contribute to the better interpretation of scatterer size estimates for characterizing anisotropic RBC aggregates in blood.

Published
2021

36. Amplitude and phase changes for reflected and transmitted waves from a curved interface in anisotropic media

Author

Paul Cristini, Nathalie Favretto-Cristini, Bjørn Ursin, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Ondes et Imagerie (O&I), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Seismic anisotropy, 010504 meteorology & atmospheric sciences, Interface (Java), Wave propagation, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Acoustics, Body waves, Phase (waves), 010502 geochemistry & geophysics, 01 natural sciences, Geophysics, Amplitude, Geochemistry and Petrology, Anisotropy, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Computational seismology
Abstract

SUMMARY It is well known that seismic data that have been recorded in complex geological environments must be compensated for geometrical spreading before AVO/AVA (amplitude-versus-offset/amplitude-versus-angle) analysis, in order to avoid erroneous imaging interpretation. By investigating analytically both the effect of the geometrical spreading and the effect of the reflector curvature on amplitude and phase changes for reflected and transmitted waves between anisotropic media, using ray theory, we show that these data should be compensated for interface effects as well. In order to gain insight more specifically in the focusing effect of the interface, the special case of homogeneous isotropic media separated by a curved interface of syncline type is discussed and compared to the case of a plane interface. 3-D numerical simulations of wave reflection from curved interfaces using a spectral element method validate our analytical derivations. In particular, numerical seismograms obtained at a vertical receiver array highlight that the effect of interface curvature on the reflected events is much more pronounced in a restricted area associated with the existence of caustics, which is consistent with our analytical predictions. Moreover, comparisons between the numerical and the analytical results confirm the fact that using plane-wave reflection coefficients without correction for the interface effect may lead to wrong interpretation of AVA/AVO analysis.

Published
2021

37. Factorization à la Dirac Applied to Some Equations of Classical Physics

Author

Zine El Abiddine Fellah, Erick Ogam, Mohamed Fellah, Claude Depollier, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), Laboratoire d'Acoustique de l'Université du Mans (LAUM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB), and Centre National de la Recherche Scientifique (CNRS)-Le Mans Université (UM)

Subjects
Basset force, Diffusion equation, factorization method, General Mathematics, Dirac (software), [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Telegrapher's equations, fractional calculus, 01 natural sciences, 010305 fluids & plasmas, 0103 physical sciences, Computer Science (miscellaneous), QA1-939, [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP], 010306 general physics, Engineering (miscellaneous), Physics, Partial differential equation, diffusion equation, telegraph equation, Wave equation, basset force, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Classical mechanics, Compressibility, Dissipative system, wave equation, Mathematics
Abstract

International audience; In this paper, we present an application of Dirac’s factorization method to three types of the partial differential equations, i.e., the wave equation, the scattering equation, and the telegrapher’s equation. This method gives results that contribute to a better understanding of physical phenomena by generalizing the Euler and constituent equations. Its application to the wave equation shows that it is indeed a factorization method, since it gives d’Alembert’s solutions in a more general framework. In the case of the diffusion equation, a fractional differential equation has been established that has already been highlighted by other authors in particular cases, but by indirect methods. Dirac’s method brings several new results in the case of the telegraphers’ equation corresponding to the propagation of an acoustic wave in a dissipative fluid. On the one hand, its formalism facilitates the temporal interpretation of phenomena, in particular the density and compressibility of the fluid become temporal operators, which can be “seen” as susceptibilities of the fluid. On the other hand, a consequence of this temporal modeling is the highlighting in Euler’s equation of a term similar to the one that was introduced by Boussinesq and Basset in the equation of the motion of a solid sphere in a unsteady fluid.

Published
2021

38. Linear and nonlinear resonant ultrasonic techniques applied to assess delayed ettringite formation on concrete samples

Author

Christophe Marquie, Florian Ouvrier-Buffet, Benoit Durville, J. N. Eiras, Narintsoa Ranaivomanana, Cédric Payan, Vincent Garnier, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), PSN-RES/SEREX, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Laboratoire Matériaux et Durabilité des constructions (LMDC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Service d'Etude et de Recherche EXpérimentale (IRSN/PSN-RES/SEREX), 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)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)

Subjects
Ettringite, Materials science, Scanning electron microscope, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, Building and Construction, 0201 civil engineering, law.invention, chemistry.chemical_compound, Nonlinear system, [SPI]Engineering Sciences [physics], Quality (physics), chemistry, Acoustic emission, Optical microscope, law, 021105 building & construction, Dynamic modulus, General Materials Science, Ultrasonic sensor, Composite material, ComputingMilieux_MISCELLANEOUS, Civil and Structural Engineering
Abstract

This study investigates the application of different ultrasonic Non-Destructive tests to assess Delayed Ettringite Formation, in concrete samples exhibiting low kinetic expansions (and up to 0.21%). Linear and nonlinear Resonant Ultrasonic Spectroscopy and Acoustic Emission tests were used. Scanning Electron Microscopy and optical microscopy observations were conducted at the end of the monitoring tests. The results showed a slight increase of the dynamic modulus and Quality factor while nonlinear hysteretic parameters remained constant over the test duration. Acoustic Emission tests attested the occurrence of events. However, the microscopic observations did not reveal meaningful differences in microcracking extent between the samples.

Published
2021

39. A penalty-free approach to PDE constrained optimization: Application to an inverse wave problem

Author

Vadim Monteiller, Alexandre Hoffmann, Cédric Bellis, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-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), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and École polytechnique (X)-Mines Paris - PSL (École nationale supérieure des mines de Paris)

Subjects
State variable, Sequence, Optimization problem, Computer Science::Information Retrieval, Applied Mathematics, [PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], Constrained optimization, Inverse, 010103 numerical & computational mathematics, Residual, 01 natural sciences, Computer Science Applications, Theoretical Computer Science, 010101 applied mathematics, Quadratic equation, Signal Processing, Applied mathematics, Quadratic programming, 0101 mathematics, Mathematical Physics, ComputingMilieux_MISCELLANEOUS, Mathematics
Abstract

Inverse wave problems (IWPs) amount in non-linear optimization problems where a certain distance between a state variable and some observations of a wavefield is to be minimized. Additionally, we require the state variable to be the solution of a model equation that involves a set of parameters to be optimized. Typical approaches to solve IWPs includes the adjoint method, which generates a sequence of parameters and strictly enforces the model equation at each iteration, and, the wavefield reconstruction inversion (WRI) method, which jointly generates a sequence of parameters and state variable but does not strictly enforce the model. WRI is considered to be an interesting approach because, by virtue of not enforcing the model at each iteration, it expands the search space, and can thus find solutions that may not be found by a typical adjoint method. However, WRI techniques generally requires the tuning of a penalty parameter until the model equation is considered satisfied. Alternatively, a fixed penalty parameter can be chosen but, in such case, it is impossible for the algorithm to find a solution that satisfies the model equation exactly. In the present work, we present a, to our knowledge, novel technique of WRI type which jointly generates a sequence of parameters and state variable, and which loosely enforces the model. The method is based on a TR-SQP method which aims at minimizing, at each iteration, both the residual relative to the linearized model and a quadratic approximation of the cost functional. Our method approximately solves a sequence of quadratic subproblems by using a Krylov method. The Hessian-vector product is computed using the second-order adjoint method. The method is demonstrated on a synthetic case, with a configuration relevant to medical imaging.

Published
2021

40. Acoustical inverse methods for bone media identification with ultrasonic reflected waves

Author

Roncen, Rémi, Fellah, Zine El Abiddine, Ogam, Erick, ONERA / DMPE, Université de Toulouse [Toulouse], ONERA-PRES Université de Toulouse, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Fellah, Zine El Abiddine, Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Porous material, Bayesian inference, Inverse method, [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Porous media represent a vast class of materials, encountered in, i.e., geology, medicine and acoustics. Knowledge of the porous microstructure is necessary for the use of the different models describing the acoustical behavior of porous media. The focus of this work is put on inverse identification methods, that allow the retrieval of several microstructural parameters of a porous material. The inverse method is based on the measurement of an acoustic field transmitted and/or reflected by the porous material, and is recast as a Bayesian inference problem. This allows for an uncertainty quantification of the identified parameters, and model selection, in case of competing models for the acoustic representation of a porous material. Different materials are tested in impedance tubes, and their properties are inferred using different acoustical models. Samples of multiple thicknesses are backed with airgaps of different length, which allows for a densification of the test matrix for a given material: this ultimately improves knowledge on the porous microstructure properties, described by posterior probability density functions in a Bayesian context.

Published
2020

41. Ultrasound Computed Tomography of children long bones using a dual-frequency transducer array

Author

Lasaygues, Philippe, Espinosa, Luis, Guillermin, Régine, Debieu, Eric, Long, Vincent, Baron, Cécile, PETIT, Philippe, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Universidad Nacional de Colombia [Bogotà] (UNAL), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences du Mouvement Etienne Jules Marey (ISM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), Institut du Mouvement et de l’appareil Locomoteur [Hôpital Sainte-Marguerite - APHM] (IML), Assistance Publique - Hôpitaux de Marseille (APHM)-Hôpital Sainte-Marguerite [CHU - APHM] (Hôpitaux Sud )-Rhumatologie [Sainte- Marguerite - APHM] ( Hôpitaux Sud), Assistance Publique - Hôpitaux de Marseille (APHM)-Hôpital Sainte-Marguerite [CHU - APHM] (Hôpitaux Sud ), GIE PSA-RENAULT, and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], Ultrasound, Bone, Tomography, Children, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; B-mode ultrasound (echography) has long been a first-line examination for the diagnosis of many diseases in children. The other modalities, such as X-ray or magnetic resonance imaging, are often associated with inconveniences of variable importance (cost, irradiation, sedation, accessibility) that are constraining for pediatric applications [1]. But B-mode ultrasound has difficulty penetrating bone and the locks associated with the in-vivo configuration are still numerous: image resolution and the contrast in the deep zone; accessibility of anatomical sites, or in between the two leg and arm bones. Ultrasonic Computed Tomography (USCT) is a relevant modality to bone tissues imaging [2], [3]. The acquisition geometry of the signals is no longer linear nor sectoral, as in B-mode ultrasound, but circular in the orthogonal plane, and based on a multiplexed dual-frequency 2D-ring antenna allowing electronical and mechanical scanning. The antenna supports 8 fixed transducers distributed over 360�. The Mistras-Eurosonic? multiplexer is equipped with an 8-by-8 parallel-channel acquisition system. The 8 transducers are Imasonic? piezo-composite transducers with a center frequency of 1MHz and 2.25MHz. Each transducer is 60 mm high and 56 mm in diameter. These transducers have cylindrical focusing with a focal length of 150 mm, a lateral aperture size of 40 mm and an axial aperture size of 30 mm. The slice thickness is 3 mm. Results obtained on rectified non-circular cylindrical tubes, on paired bones (Sawbones�) are presented. References [1] P. Petit et al., ?Am. J. Roentgenol., vol. 176, no. 4, pp. 987?990, Apr. 2001. [2] P. Lasaygues et al., Proceedings of the Int. Workshop on MUST, Speyer, Germany, 2017. [3] S. Bernard, et al., Phys. Med. Biol., vol. 62, no. 17, pp. 7011?7035, Aug. 2017. Acknowledgements This research was supported by the Provence-Alpes-Côte d'Azur ? PACA Regional Council, under Grant No.2016₀2696.

Published
2020

42. Reduced-scale lab experiments : a valuable tool for exploring current challenges of seismic surveying, modeling and imaging in complex marine environments at a low cost and in an agile way ?

Author

Favretto-Cristini, Nathalie, Solymosi, Bence, Monteiller, Vadim, Cristini, Paul, Ursin, Bjorn, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Ondes et Imagerie (O&I), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Recently, laboratory experiments have been reintroduced in the ideas-to-applications pipeline for geophysical issues. Benefiting from recent technological advances, laboratory experiments may play a major role in the coming years, in support of field experiments and numerical modeling, to explore some of the current challenges of seismic imaging in terms of, for instance, acquisition design or benchmarking of new imaging techniques at a low cost and in an agile way. But having confidence in the quality and the accuracy of the experimental data obtained in a complex configuration that mimics at a reduced scale a real geological environment is an essential prerequisite. This requires a robust framework regardless of the configuration studied. The goal of this work is to provide a global reflection on this framework in the context of offshore seismics. To illustrate this framework, we rely on different reduced-scale models, and more specifically on a model that represents a 3D complex-shaped salt body buried in sedimentary layers with curved surfaces. Zero-offset and offset reflection data are collected on this model in a water tank, using a conventional pulse-echo technique. We follow a cross-validation approach that allows, through the comparison between the experimental data and the numerical simulation of wave propagation, to point out both the improvements of the experimental setup that must still be made to increase the accuracy of the experiments, and the limitations of the numerical tools that must be tackled. This framework can be used with confidence to extensively investigate cutting-edge seismic modeling and imaging and acquisition issues in complex environments.

Published
2020

43. Seismo-acoustic wave propagation in the Rade of Hyères (France) generated by counter-mining of explosive devices : risk assessment from the comparison between numerical simulations and real experiments

Author

Favretto-Cristini, Nathalie, Wang, Fang, Garlan, Thierry, Morio, Olivier, Deschamps, Anne, Ambrois, David, Mercerat, Diego, Demoulin, Xavier, Beucler, Éric, Bonnin, Mickaël, Cristini, Paul, Monteiller, Vadim, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Shenzhen University [Shenzhen], Service Hydrographique et Océanographique de la Marine (SHOM), Ministère de la Défense, Géoazur (GEOAZUR 7329), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [France-Sud]), Centre d'études et d'expertise sur les risques, l'environnement, la mobilité et l'aménagement - Equipe-projet Repsody (Equipe-projet Repsody), Centre d'Etudes et d'Expertise sur les Risques, l'Environnement, la Mobilité et l'Aménagement (Cerema), Auteur indépendant, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire des Sciences de l'Univers Nantes Atlantiques (OSUNA), Université d'Angers (UA)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université Gustave Eiffel, Ondes et Imagerie (O&I), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université d'Angers (UA)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-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)-IMT Atlantique (IMT Atlantique), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], underwater acoustics, interface waves, seismics, 13. Climate action, counter-mining, 14. Life underwater, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Explosive devices from World War II are discovered almost every week on the French coasts and they must be destroyed by the French Navy Mine Warfare Office. The consequences of the counter-mining on the marine environment are complex to evaluate. Depending on the environment geology, the explosive charges and their localization, the seismo-acoustic waves generated by the explosion may cause damage to infrastructures located on the coast, and under specific conditions small submarine landslides. The ANR ASTRID POSA project proposed to address the risk assessment issue on the Mediterranean coast. The main originality of this project lied in the approach used that combines geological measurements, acoustic data recorded within the sea coastal zone and seismic data recorded on the coast, together with numerical simulations of seismo-acoustic wave propagation. We propose here to present the results of such a methodology applied to the counter-mining campaign that occurred in the Rade of Hyères (France) in December 2018. We focus more specifically on the numerical simulations of seismo-acoustic wave propagation from the location of the device explosion to several seismometers deployed on the coast of Hyères. From topographical and sedimentary measurements performed in the Rade of Hyères, physical and geometrical characteristics of the marine seabed have been carefully selected as input data for numerical simulations. In addition, a particular attention has been paid to the measured characteristics of the device explosion (source). The numerical simulations have then been conducted using a spectral-element method. The impact of the explosive device charge and its location (on the seabed or in the water column), together with the impact of the marine environment properties, on the simulated signals have been studied. Finally, the numerical results have been compared with the real signals recorded by the seismometers. The risks of land degradation have been evaluated afterwards.

Published
2020

44. On the Influence of Slopes, Source, Seabed and Water Column Properties on T Waves: Generation at Shore

Author

Dimitri Komatitsch, Alexis Bottero, Paul Cristini, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Shore, geography, geography.geographical_feature_category, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Acoustic wave, 010502 geochemistry & geophysics, 01 natural sciences, Seafloor spreading, Term (time), Physics::Geophysics, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Geophysics, Water column, 13. Climate action, Geochemistry and Petrology, Position (vector), Speed of sound, Geology, Seabed, Seismology, 0105 earth and related environmental sciences
Abstract

International audience; The term T waves is generally associated with acoustic waves generated by seismic events that subsequently travel horizontally in the ocean at the speed of sound. In this paper, we use a time-domain spectral-element method to perform a parametric study of the influence of seafloor slope, source position and media properties for a typical (downslope) T-wave generation scenario. We find that the energy and duration of these waves are particularly sensitive to the environment. In particular, the slopes and physical characteristics of the seabed play a crucial role for both the generation and the conversion of these waves. Likewise, the depth and position of the earthquake relative to the slope is of great importance, with the presence of privileged areas for the generation of T waves, which we map.

Published
2020

45. Quantifying scattering from dense media using two-dimensional impedance maps

Author

Kenji Yoshida, Tadashi Yamaguchi, Jonathan Mamou, Kazuki Tamura, Emilie Franceschini, Hamamatsu University Medical School of Medicine, F. L. Lizzi Center for Biomedical Engineering, Riverside Research, Chiba University, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Materials science, [SDV.BIO]Life Sciences [q-bio]/Biotechnology, Acoustics and Ultrasonics, Correlation coefficient, Scattering, Isotropy, Mathematical analysis, [SPI.MECA.BIOM]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Biomechanics [physics.med-ph], 01 natural sciences, Ellipsoid, 030218 nuclear medicine & medical imaging, 03 medical and health sciences, symbols.namesake, 0302 clinical medicine, Fourier transform, Arts and Humanities (miscellaneous), 0103 physical sciences, symbols, SPHERES, Structure factor, 010301 acoustics, Electrical impedance
Abstract

International audience; A better understanding of ultrasound scattering in a three-dimensional (3D) medium can provide more accurate methods for ultrasound tissue characterization. The possibility of using two-dimensional impedance maps (2DZMs) based on correlation coefficients has shown promise in the case of isotropic and sparse medium [Luchies and Oelze, J. Acoust. Soc. Am. 139, 1557-1564 (2016)]. The present study investigates the use of 2DZMs in order to quantify 3D scatterer properties of dense media from two-dimensional (2D) histological slices. Two 2DZM approaches were studied: one based on the correlation coefficient and the other based on the 2D Fourier transform of 2DZMs. Both 2DZM approaches consist in estimating the backscatter coefficient (BSC) from several 2DZMs, and then the resulting BSC was fit to the theoretical polydisperse structure factor model to yield 3D scatterer properties. Simulation studies were performed to evaluate the ability of both 2DZM approaches to quantify scattering of a 3D medium containing randomly distributed polydisperse spheres or monodisperse ellipsoids. Experimental studies were also performed using the histology photomicrographs obtained from HT29 cell pellet phantoms. Results demonstrate that the 2DZM Fourier transform-based approach was more suitable than the correlation coefficient-based approach for estimating scatterer properties when using a small number of 2DZMs.

Published
2020

46. Internal Pressure Monitoring in a Post-tensioned Containment Building Using Operational Vibration

Author

Vincent Garnier, J. N. Eiras, Gonzalo Cetrangolo, Cédric Payan, Agustin Spalvier, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, business.industry, Mechanical Engineering, education, Containment building, 0211 other engineering and technologies, Internal pressure, 02 engineering and technology, Structural engineering, Accelerometer, 01 natural sciences, Finite element method, Vibration, [SPI]Engineering Sciences [physics], Nonlinear system, Mechanics of Materials, 021105 building & construction, 0103 physical sciences, Solid mechanics, business, 010301 acoustics, ComputingMilieux_MISCELLANEOUS, Leakage (electronics)
Abstract

Nuclear material containment buildings are required to be periodically inspected to assure good quality conditions. To this end, there is increasing interest in developing efficient and economical testing techniques to monitor and inspect these structures. In this paper we study the dynamic behavior of a 1/3 mock-up containment structure and its internal pressure-dependence using testing techniques that may not interfere with the structure’s operation. The goal is to assess the possibility of monitoring internal pressure and potential leakage by measuring the structural frequency of vibration. The Vercors mock-up structure, a post-tensioned double-wall concrete structure of dimensions 15 m diameter and 30 m tall, was internally pressurized from 0 to 4 bar. We attached a pair of accelerometers at the outer surface of the inner structure and recorded signals periodically without imposing any controlled dynamic input; thus, we used an output-only dynamic analysis. We found that there is a clear positive correlation between internal pressure and the identified frequencies of vibration. We developed a multi-variable correlation, using several frequencies of vibration and the measured pressure, which could be used to monitor internal pressure. To study the underlying physical behavior, we built a finite element model. The observed frequency shift due to applied internal pressure could be partially explained by the effect of geometric nonlinearity, but it does not explain the entire range of frequency shift. Material nonlinearity should also be considered to assess this problem.

Published
2020

47. Bistatic scattering of an elastic object using the structural admittance and noise-based holographic measurements

Author

Earl G. Williams, Jit Sarkar, Simone Sternini, Sandrine T. Rakotonarivo, Alexis Bottero, William A. Kuperman, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Admittance, Acoustics and Ultrasonics, Field (physics), Acoustics, Shell (structure), Conformal map, Rigid body, 01 natural sciences, Noise (electronics), Admittance parameters, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], 03 medical and health sciences, Bistatic radar, 0302 clinical medicine, Arts and Humanities (miscellaneous), 0103 physical sciences, 030223 otorhinolaryngology, 010301 acoustics, ComputingMilieux_MISCELLANEOUS
Abstract

This paper presents a method to calculate the bistatic response of an elastic object immersed in a fluid using its structural Green's function (in vacuo structural admittance matrix), calculated by placing the object in a spatially random noise field in air. The field separation technique and equivalent source method are used to reconstruct pressure and velocity fields at the object's surface from pressure measurements recorded on two conformal holographic surfaces surrounding the object. Accurate reconstruction of the surface velocity requires subtraction of the rigid body response computed using a finite element approach. The velocity and pressure fields on the surface lead to the extraction of the in vacuo structural admittance matrix of the elastic object, which is manipulated to yield the farfield bistatic response for a fluid-loaded target for several angles of incidence. This method allows the computation of the scattering properties of an elastic object using exclusive information calculated on its surface (no knowledge of the internal structure required). A numerical experiment involving a cylindrical shell with hemispherical caps is presented, and its bistatic response in water shows excellent agreement with a finite element solution.

Published
2020

48. Quantitative ultrasound imaging for the diagnostic of the integrity of growing biological materials

Author

Espinosa, Luis, Monteiller, Vadim, Bernard, Simon, Guillermin, Régine, Brancheriau, Loïc, Lasaygues, Philippe, Universidad Nacional de Colombia [Bogotà] (UNAL), Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Equipe Apprentissage (DocApp - LITIS), Laboratoire d'Informatique, de Traitement de l'Information et des Systèmes (LITIS), Université Le Havre Normandie (ULH), Normandie Université (NU)-Normandie Université (NU)-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)-Université Le Havre Normandie (ULH), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), BioWooEB (UPR BioWooEB), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Département Performances des systèmes de production et de transformation tropicaux (Cirad-PERSYST), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Université de Montpellier (UM)

Subjects
[PHYS.MECA.VIBR]Physics [physics]/Mechanics [physics]/Vibrations [physics.class-ph], FWI, Bone, Wood, Ultrasound imaging, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Long bones and green wood are two living materials with close structural characteristics. They evolve with age and they are in constant adaption to the environmental constraints. Their mechanical properties vary in successive stages from the juvenile state to the mature state. The study of the quality of these materials to improve the management of dysfunctions is the subject of advanced research. Quantitative ultrasound techniques have been previously used to evaluate bone quality, by giving information about the bone mechanical parameters. For trees, acoustic and ultrasound non-destructive imaging methods have been recently used to analyze their inner structures without altering their condition. This study aims to conduct a theoretical, numerical and experimental joint study of these two materials, in order to propose an efficient and optimized procedure for the characterization and cross-section imaging of growing living materials such as long bones or tree trunks. First, the interaction of acoustic waves with the growing material is modeled, to analyze the phenomena of wave interaction with these complex materials. Then, in order to solve the inverse problem, the Full Waveform Inversion (FWI) method is used. The imaging method is validated using measurements from reference materials.

Published
2020
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49. A penatly-free approach to PDE constrained optimization: Application to an inverse wave problem

Author

Hoffmann, Alexandre, Monteiller, Vadim, Bellis, Cédric, Ondes et Imagerie (O&I), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de mécanique des solides (LMS), École polytechnique (X)-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), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
[PHYS.MPHY]Physics [physics]/Mathematical Physics [math-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2020

50. Seismic surveying and imaging at the laboratory scale: A framework to cross-validate experiments and simulations for a salt-body environment

Author

V. Monteiller, Dimitri Komatitsch, Paul Cristini, Bence Solymosi, Nathalie Favretto-Cristini, Bjørn Ursin, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), Ondes et Imagerie (O&I), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], Petroleum engineering, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Seismic migration, Laboratory scale, 010502 geochemistry & geophysics, 01 natural sciences, Pipeline (software), Geophysics, Geochemistry and Petrology, 0103 physical sciences, 010301 acoustics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract

International audience; Laboratory experiments have been recently reintroduced into the ideas-to-applications pipeline for geophysical applications. Benefiting from recent technological advances, we believe that in the coming years, laboratory experiments can play a major role in supporting field experiments and numerical modeling, to explore some of the current challenges of seismic imaging in terms of, for instance, acquisition design or benchmarking of new imaging techniques at a low cost and in an agile way. But having confidence in the quality and accuracy of the experimental data obtained in a complex configuration which mimics at a reduced scale a real geologic environment, is an essential prerequisite. This requires a robust framework regardless of the configuration studied. Our goal is to provide a global overview of this framework in the context of offshore seismics. To illustrate it, a reduced-scale model is used to represent a 3D complex-shaped salt body buried in sedimentary layers with curved surfaces. Zero-offset and offset reflection data are collected in a water tank, using a conventional pulse-echo technique. Then a cross-validation approach is applied, which allows through the comparison between the experimental data and the numerical simulation, to point out both some necessary future improvements of the laboratory setup to increase the accuracy of the experimental data, and the limitations of the numerical implementation which must also be tackled. Due to this approach, a hierarchical list of points can be collected, to which particular attention should be paid in order to make laboratory experiments an efficient tool in seismic exploration. Finally, the quality of both the complex reduced-scale model and the global framework is successfully validated by applying reverse-time migration to the laboratory data.

Published
2020

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