Search

Your search keyword '"Mercier, Sebastien"' showing total 41 results
Start Over Author "Mercier, Sebastien"
41 results on '"Mercier, Sebastien"'

1. An additive Mori-Tanaka scheme for elastic-viscoplastic composites based on a modified tangent linearization

Author

Kowalczyk-Gajewska, Katarzyna, Berbenni, Stephane, and Mercier, Sebastien

Subjects
Physics - Computational Physics, Condensed Matter - Materials Science
Abstract

Mean-field modeling based on the Eshelby inclusion problem poses some difficulties when the non-linear Maxwell-type constitutive law is used for elasto-viscoplasticity. One difficulty is that this behavior involves different orders of time differentiation, which leads a long-term memory effect. One of the possible solutions to this problem is the additive interaction law. Generally, mean field models solely use the mean values of stress and strain fields per phase, while variational approaches consider the second moments of stresses and strains. It is seen that the latter approach improves model predictions allowing to account for stress fluctuation within the phases. However, the complexity of the variational formulations still makes them difficult to apply in the large scale finite element calculations and for non-proportional loadings. Thus, there is a need to include the second moments within homogenization models based on the additive interaction law. In the present study, the incorporation of the second moments of stresses into the formulation of the additive Mori-Tanaka model of two-phase elastic-viscoplastic material is discussed. A modified tangent linearization of the viscoplastic law is proposed, while the Hill-Mandel's lemma is used to track the evolution of second moments of stresses. To study the model performance and efficiency, the results are compared to the full-field numerical calculations and predictions of other models available in the literature. Very good performance of the modified tangent linearization is demonstrated from these benchmarks for both monotonic and non monotonic loading responses., Comment: 30 pages, 8 figures (preprint of accepted article send to Mechanics of Materials)

Published
2024
Full Text
View/download PDF

12. Homogeneization of Viscoplastic Materials

Author

Molinari, Alain, Mercier, Sébastien, Gladwell, G. M. L., editor, Ahzi, S., editor, Cherkaoui, M., editor, Khaleel, M. A., editor, Zbib, H. M., editor, Zikry, M. A., editor, and Lamatina, B., editor

Published
2004
Full Text
View/download PDF

14. Conformation-specific spectroscopy and photodissociation of cold, protonated tyrosine and phenylalanine

Author

Stearns, Jaime A., Mercier, Sebastien, Seaiby, Caroline, Guidi, Monia, Boyarkin, Oleg V., and Rizzo, Thomas R.

Subjects
Infrared spectroscopy -- Usage, Tryptophan -- Chemical properties, Tyrosine -- Research, Chemistry
Abstract

Ultraviolet and infrared spectra of protonated aromatic amino acids, protonated and phenylalanine, are presented in a cold, 22-pole ion trap. The results have shown that the degree of excited-state fragmentation is both molecule- and conformer-dependent.

Published
2007

15. Infrared spectroscopy of hydrated amino acids in the gas phase: Protonated and lithiated valine

Author

Kamariotis, Anthi, Mercier, Sebastien R., Beck, Rainer D., Boyarkin, Oleg V., Bush, Matthew F., Williams, Evan R., and Rizzo, Thomas R.

Subjects
Amino acids -- Chemical properties, Hydrates -- Chemical properties, Lithium compounds -- Chemical properties, Infrared spectroscopy -- Usage, Chemistry
Abstract

The infrared spectra of protonated and lithiated valine with varying degrees of hydration in the gas phase is reported and interpreted with the help of DFT calculations at the B3LYP/6-31++G level. It is seen that infrared spectroscopy provides valuable information on the structure of solvated biological molecules in the gas phase that complements data obtained by blackbody infrared radiative dissociation studies.

Published
2006

18. Simulation of the failure of ductile materials under dynamic loading using continuum damage models with micro-inertia

Author

Jacques, Nicolas, Mercier, Sebastien, Molinari, Alain, Institut de Recherche Dupuy de Lôme (IRDL), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Brest (UBO)-Université de Bretagne Sud (UBS), École Nationale Supérieure d'Arts et Métiers (ENSAM), and HESAM Université (HESAM)-HESAM Université (HESAM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Structural mechanics [physics.class-ph], [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], ComputingMilieux_MISCELLANEOUS, [SPI.MECA.STRU]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Mechanics of the structures [physics.class-ph]
Abstract

International audience

Published
2018

19. Dynamic flow surface of porous materials containing spheroidal void shape

Author

Mercier, Sebastien, Sartori, Cédric, Jacques, Nicolas, Molinari, Alain, ONERA - The French Aerospace Lab ( Chatillon ), ONERA, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux ( LEM3 ), Arts et Métiers ParisTech-Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de Recherche Dupuy de Lôme ( IRDL ), Centre National de la Recherche Scientifique ( CNRS ) -ENSTA Bretagne-Université de Brest ( UBO ) -Université de Bretagne Sud ( UBS ), ONERA - The French Aerospace Lab [Châtillon], Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), École Nationale Supérieure d'Arts et Métiers (ENSAM), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche Dupuy de Lôme (IRDL), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Brest (UBO)-Université de Bretagne Sud (UBS), Université de Lorraine (UL)-École Nationale Supérieure d'Arts et Métiers (ENSAM), HESAM Université (HESAM)-HESAM Université (HESAM)-Centre National de la Recherche Scientifique (CNRS), Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Centre National de la Recherche Scientifique (CNRS), ONERA-Université Paris Saclay (COmUE), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), and Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Université de Bretagne Sud (UBS)

Subjects
[PHYS]Physics [physics], [ PHYS ] Physics [physics], [PHYS.MECA]Physics [physics]/Mechanics [physics], [ PHYS.MECA ] Physics [physics]/Mechanics [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2017

20. The infrared and ultraviolet spectra of single conformations of methyl-capped dipeptides: N-acetyl tryptophan amide and N-acetyl tryptophan methyl amide.

Author

Dian, Brian C., Longarte, Asier, Mercier, Sebastien, Evans, David A., Wales, David J., and Zwier, Timothy S.

Subjects
PEPTIDES, CONFORMATIONAL analysis, INFRARED spectroscopy, ULTRAVIOLET spectroscopy
Abstract

A combination of methods, including laser-induced fluorescence excitation, fluorescence-dip infrared (FDIR) spectroscopy, and UV-UV hole-burning spectroscopy, have been used to study the infrared and ultraviolet spectra of single conformations of two methyl-capped dipeptides: N-acetyl tryptophan amide (NATA) and N-acetyl tryptophan methyl amide (NATMA). Density functional theory calculations predict that all low-energy conformers of NATA and NATMA belong to one of two conformational families: C5, with its extended dipeptide backbone, or C7[sub eq], in which the dipeptide backbone forms a seven-membered ring joined by a H bond between the ψ-amide NH and the ψ-amide carbonyl groups. In NATA (NATMA), the LIF spectrum has contributions from two (three) conformers. FDIR spectroscopy has been used to record infrared spectra of the individual conformers over the 2800-3600 cm[sup -1] region, free from interference from one another. The NH stretch region provides unequivocal evidence that one of the conformers of NATA is C5, while the other is C7[sub eq]. Similarly, in NATMA, there are two C5 conformers, and one C7[sub eq] structure. Several pieces of evidence are used to assign spectra to particular C5 and C7[sub eq] conformers. NATA(A) and NATMA(B) are both assigned as C5(AP) structures, NATA(B) and NATMA(C) are assigned as C7[sub eq] (ΦP), and NATMA(A) is assigned as C5(AΦ). In both molecules, the C5 structures have sharp vibronic spectra, while the C7[sub eq] conformers are characterized by a dense, highly congested spectrum involving long progressions that extend several hundred wave numbers to the red of the C5 S[sub 1]-S[sub 0] origins. N-acetyl tryptophan ethyl ester (NATE), which can only form C5 conformers, shows only sharp transitions in its LIF spectrum due to four C5 conformers, with no evidence for the broad absorption due to C7[sub eq]. This provides direct experimental evidence for the importance of the peptide backbone conformation in... [ABSTRACT FROM AUTHOR]

Published
2002
Full Text
View/download PDF

21. Microsolvation effects on the excited-state dynamics of protonated tryptophan

Author

Mercier, Sebastien R., Boyarkin, Oleg V., Kamariotis, Anthi, Guglielmi, Matteo, Rothlisberger, Ursula, Tavernelli, Ivano, Cascella, Michele, and Rizzo, Thomas R.

Subjects
Tryptophan -- Chemical properties, Amino acids -- Chemical properties, Amino acids -- Physiological aspects, Chemistry
Abstract

The electronic spectra of a protonated, gas-phase tryptophan solvated with a controlled number of water molecules is observed and studied to understand the complex photophysics of amino acid tryptophan, which is commonly used as a probe of protein structure and dynamics. The results clearly state that the addition of water molecules highly destabilizes the photodissociative states of the tryptophans, and hence also yields an increased lifetime of their excited-state.

Published
2006

22. Electronic spectroscopy of cold, protonated tryptophan and tyrosine

Author

Boyarkin, Oleg V., Mercier, Sebastien R., Kamariotis, Anthi, and Rizzo, Thomas R.

Subjects
Tyrosine -- Chemical properties, Tyrosine -- Spectra, Tyrosine -- Electric properties, Tryptophan -- Chemical properties, Tryptophan -- Spectra, Tryptophan -- Electric properties, Chemistry
Abstract

A new method is described to obtain electronic spectra of charged biological molecules produced in the gas phase by electrospray and cooled to approximately 10 K in a radio frequency (RF) ion trap and the electronic spectra of cold, protonated tryptophan (TrpH(super +)) and tyrosine (TyrH(super +)). The ability to cool biomolecular ions in the gas phase to low internal temperatures helps in applying spectroscopic techniques to a wide range of large molecules that can be produced in the gas phase by electrospray.

Published
2006

24. Some aspects of inertia in porous ductile solids subjected to dynamic loadings

Author

Jacques, Nicolas, Mercier, Sebastien, Mollinari, C., DFMS, Laboratoire brestois de mécanique et des systèmes (LBMS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, and HESAM Université (HESAM)-HESAM Université (HESAM)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2013

25. Dynamic damage and fracture of ductile materials

Author

Molinari, Alain, Jacques, Nicolas, Mercier, Sebastien, Leal, Nathalie, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), DFMS, Laboratoire brestois de mécanique et des systèmes (LBMS), and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2013

26. Beijing

Author

Mercier, Sebastien, Jacques, Nicolas, Molinari, A., Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), DFMS, Laboratoire brestois de mécanique et des systèmes (LBMS), and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012

27. Multiscale modelling of voided ductile solids with micro-inertia and application to dynamic crack propagation

Author

Jacques, Nicolas, Mercier, Sebastien, Molinari, A., DFMS, Laboratoire brestois de mécanique et des systèmes (LBMS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), and Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies

Published
2012

28. Effets micro-inertiels lors de la propagation dynamique de fissures ductiles

Author

Jacques, Nicolas, Mercier, Sebastien, Molinari, A., DFMS, Laboratoire brestois de mécanique et des systèmes (LBMS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Arts et Métiers Sciences et Technologies, HESAM Université (HESAM)-HESAM Université (HESAM), and Arts et Métiers Sciences et Technologies

Published
2012

29. Influence of micro inertia on dynamic damage, application to fracture of ductile materials

Author

Jacques, Nicolas, Mercier, Sebastien, Molinari, Alain, Laboratoire brestois de mécanique et des systèmes (LBMS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Laboratoire de physique et mécanique des matériaux (LPMM), Université Paul Verlaine - Metz (UPVM)-Institut National Polytechnique de Lorraine (INPL)-Ecole Nationale d'Ingénieurs de Metz (ENIM)-Centre National de la Recherche Scientifique (CNRS), and Leal, Nathalie

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

30. Microinertia effects on dynamic crack propagation in ductile materials

Author

Jacques, Nicolas, Mercier, Sebastien, Molinari, Alain, Leal, Nathalie, Laboratoire brestois de mécanique et des systèmes (LBMS), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Laboratoire de physique et mécanique des matériaux (LPMM), and Université Paul Verlaine - Metz (UPVM)-Institut National Polytechnique de Lorraine (INPL)-Ecole Nationale d'Ingénieurs de Metz (ENIM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2011

31. SOUND ABSORPTION DEVICE

Author

Auffray, Nicolas, Bacos, M.-P., Bouchet, Régis, Marcadon, Vincent, Mercier, Sebastien, Josso, P., Auffray, Nicolas, ONERA - The French Aerospace Lab [Châtillon], and ONERA-Université Paris Saclay (COmUE)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Published
2011

37. Beijing

Author

Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Mercier, Sebastien, Jacques, Nicolas, Molinari, A., Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Mercier, Sebastien, Jacques, Nicolas, and Molinari, A.

Abstract

International audience

38. On the influence of microscale inertia on dynamic ductile crack extension.

Author

DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, Jacques, Nicolas, Mercier, Sebastien, Molinari, A., DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, Jacques, Nicolas, Mercier, Sebastien, and Molinari, A.

Abstract

International audience

39. Modélisation du comportement mécanique des matériaux poreux sous chargement dynamique avec prise en compte de l'effet de forme des cavités

Author

Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Sartori, C., Mercier, Sebastien, Jacques, Nicolas, Molinari, Alain, Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux (LEM3) ; CNRS - Arts et Métiers ParisTech - Université Henri Poincaré - Nancy I - Ecole Nationale d'Ingénieurs de Metz - Université de Lorraine, DFMS ; Laboratoire brestois de mécanique et des systèmes (LBMS) ; Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest - Université de Bretagne Occidentale (UBO) - Institut Supérieur des Sciences et Technologies de Brest (ISSTB) - ENSTA Bretagne - Ecole Nationale d'Ingénieurs de Brest, Sartori, C., Mercier, Sebastien, Jacques, Nicolas, and Molinari, Alain

Abstract

National audience

40. Validation of an interaction law for the Eshelby inclusion problem in elasto-viscoplasticity

Author

Alain Molinari, Sébastien Mercier, Nicolas Jacques, Laboratoire de physique et mécanique des matériaux (LPMM), Université Paul Verlaine - Metz (UPVM)-Institut National Polytechnique de Lorraine (INPL)-Ecole Nationale d'Ingénieurs de Metz (ENIM)-Centre National de la Recherche Scientifique (CNRS), Mercier, Sebastien, Laboratoire brestois de mécanique et des systèmes (LBMS), and École Nationale d'Ingénieurs de Brest (ENIB)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)

Subjects
Work (thermodynamics), Materials science, 02 engineering and technology, [SPI.MECA.SOLID]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Solid mechanics [physics.class-ph], [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], symbols.namesake, Matrix (mathematics), [PHYS.MECA.MEMA] Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], 0203 mechanical engineering, [PHYS.MECA.SOLID]Physics [physics]/Mechanics [physics]/Solid mechanics [physics.class-ph], General Materials Science, 10. No inequality, Viscoplasticity, Applied Mathematics, Mechanical Engineering, Elastic-viscoplastic materials, Strain rate, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Finite element method, Interaction law, Nonlinear system, 020303 mechanical engineering & transports, Maxwell's equations, Inclusion problem, Mechanics of Materials, Modeling and Simulation, Law, symbols, Inclusion (mineral), 0210 nano-technology
Abstract

International audience; The nonlinear Eshelby problem is considered for an elastic viscoplastic inclusion. An approximate solution has been proposed by [Molinari et al., 1997. On the self-consistent modelling of elastic–plastic behavior of polycrystals. Mech. Mater. 26, 43–62] who have postulated a simplified interaction law. With this interaction law, the average strain rate in the inclusion can be related to the far field loading prescribed in the matrix. In the present work, the matrix and the inclusion have elastic-viscoplastic behavior described by a nonlinear Maxwell law. Comparisons between predictions derived from the interaction law and finite element results are performed. It is observed that the approximate solution is in good agreement with numerical results as far as average strain rates and stresses are considered in the inclusion. Various inclusion shapes, material parameters and loading conditions are taken into account.

Published
2005
Full Text
View/download PDF

41. Modelling of nucleation and void growth in dynamic pressure loading, application to spall test on tantalum

Author

Sébastien Mercier, Alain Molinari, Christophe Czarnota, Laboratoire de physique et mécanique des matériaux (LPMM), Université Paul Verlaine - Metz (UPVM)-Institut National Polytechnique de Lorraine (INPL)-Ecole Nationale d'Ingénieurs de Metz (ENIM)-Centre National de la Recherche Scientifique (CNRS), and Mercier, Sebastien

Subjects
Void (astronomy), Materials science, Ductile fracture, Computational Mechanics, Nucleation, 02 engineering and technology, [PHYS.MECA.MEMA]Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], [PHYS.MECA.MEMA] Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph], 0203 mechanical engineering, Forensic engineering, Porosity, Coalescence (physics), Nucleation and growth, Fracture mechanics, Mechanics, 021001 nanoscience & nanotechnology, Spall, Dynamics, 020303 mechanical engineering & transports, Mechanics of Materials, Modeling and Simulation, Cavitation, Micro-inertia, 0210 nano-technology, Material properties
Abstract

Dynamic ductile fracture is a three stages process controlled by nucleation, growth and finally coalescence of voids. In the present work, a theoretical model, dedicated to nucleation and growth of voids during dynamic pressure loading, is developed. Initially, the material is free of voids but has potential sites for nucleation. A void nucleates from an existing site when the cavitation pressure p c is reached. A Weibull probability law is used to describe the distribution of the cavitation pressure among potential nucleation sites. During the initial growth, the effect of material properties is essentially appearing through the magnitude of p c. In the later stages, the matrix softening due to the increase of porosity has to be taken into account. In a first step, the response of a sphere made of dense matrix but containing a unique potential site, is investigated. When the applied loading is a pressure ramp, a closed form solution is derived for the evolution of the void that has nucleated from the existing site. The solution appears to be valid up to a porosity of 0.5. In a second part, the dynamic ductile fracture of a high-purity grade tantalum is simulated using the proposed model. Spall stresses for this tantalum are calculated and are in close agreement with experimental levels measured by Roy (2003, Ph.D. Thesis, Ecole Nationale Superieure de Mecanique et d’Aeronautique, Universite de Poitiers, France). Finally, a parametric study is performed to capture the influence of different parameters (mass density of the material, mean spacing between neighboring sites, distribution of nucleation sites...) on the evolution of damage.

Catalog

Books, media, physical & digital resources
See catalog results