Coumba Mbodj, Guillaume Peillex, Mathieu Renouf, L. Baillet, Y. Berthier, P. Jacquemard
Ce travail propose une approche numerique pour l'etude de materiaux composites carbone/carbone sous sollicitations dynamiques et conditions de contact frottant. Elle repose sur l'utilisation d'une approche elements finis (E.F.) et de techniques d'homogeneisation appliquees a une cellule elementaire du materiau. Les effets du contraste des proprietes elastiques au contact sont etudies et l'influence de la description du materiau sur le comportement tribologique est mise en evidence.
{"title":"Influence du « contraste » des propriétés élastiques des composites carbone/carbone (C/C) sous conditions dynamiques de contact frottant","authors":"Coumba Mbodj, Guillaume Peillex, Mathieu Renouf, L. Baillet, Y. Berthier, P. Jacquemard","doi":"10.1051/MECA/2010051","DOIUrl":"https://doi.org/10.1051/MECA/2010051","url":null,"abstract":"Ce travail propose une approche numerique pour l'etude de materiaux composites carbone/carbone sous sollicitations dynamiques et conditions de contact frottant. Elle repose sur l'utilisation d'une approche elements finis (E.F.) et de techniques d'homogeneisation appliquees a une cellule elementaire du materiau. Les effets du contraste des proprietes elastiques au contact sont etudies et l'influence de la description du materiau sur le comportement tribologique est mise en evidence.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"5 1","pages":"289-294"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79855343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emmanuel de Luycker, P. Boisse, F. Morestin, David Marsal, S. Otin
This work is a contribution to the simulation of composite forming. The performing of interlock reinforcement is considered in the present paper. They are 3D textile reinforcements that avoid the delamination that can occur in the case of laminate composites. A 3D semi-discrete finite element that allows to model the deformation of an interlock perform is described. Each three-dimensional element contains some fibres that contribute to the element stiffness. The material parameters are identified from mechanical tests and the simulation is validated by comparison with experiment.
{"title":"Simulation du préformage de renforts composites textiles 3D","authors":"Emmanuel de Luycker, P. Boisse, F. Morestin, David Marsal, S. Otin","doi":"10.1051/MECA/2010031","DOIUrl":"https://doi.org/10.1051/MECA/2010031","url":null,"abstract":"This work is a contribution to the simulation of composite forming. The performing of interlock reinforcement is considered in the present paper. They are 3D textile reinforcements that avoid the delamination that can occur in the case of laminate composites. A 3D semi-discrete finite element that allows to model the deformation of an interlock perform is described. Each three-dimensional element contains some fibres that contribute to the element stiffness. The material parameters are identified from mechanical tests and the simulation is validated by comparison with experiment.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"2013 1","pages":"197-202"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86452776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ductile tearing resistance of steels is generally characterized in terms of resistance curves giving the increase of a resistance parameter such as the crack driving force J or a crack opening displacement as a function of the crack extension Δa. Welded joints are often the weakest part of structures because of greater risk of defects, heterogeneity of the microstructure of the weld, strain concentration along mismatched interfaces. This paper recalls the transferability issues common to all integrity assessments based on tearing resistance curves and points out the difficulties of characterization specific to welds. Several recommendations are proposed for the experimental determination of tearing resistance of welded joints.
{"title":"Détermination de courbes de résistance à la déchirure ductile dans les joints soudés","authors":"P. Gilles, S. Marie, P. Ould","doi":"10.1051/MECA/2010038","DOIUrl":"https://doi.org/10.1051/MECA/2010038","url":null,"abstract":"The ductile tearing resistance of steels is generally characterized in terms of resistance curves giving the increase of a resistance parameter such as the crack driving force J or a crack opening displacement as a function of the crack extension Δa. Welded joints are often the weakest part of structures because of greater risk of defects, heterogeneity of the microstructure of the weld, strain concentration along mismatched interfaces. This paper recalls the transferability issues common to all integrity assessments based on tearing resistance curves and points out the difficulties of characterization specific to welds. Several recommendations are proposed for the experimental determination of tearing resistance of welded joints.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"1 1","pages":"189-196"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72655872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Julien Halgrin, F. Chaari, Eric Markiewicz, P. Drazetic
Car manufacturers use virtual human models in order to ensure the passengers safety during crash events. To improve the bio-fidelity of these models, we propose to identify the mechanical behaviour of bone tissues, and more particularly of the cancellous bone. After scanning cancellous bone samples with micro computed tomography, compression tests have been performed. The inter and intra-individual variabilities have been studied in order to minimise the results dispersions. Numerical models (taking into account the real architecture of this tissue) have been generated from the data coming from μCT in order to study the effects of architectural parameters on the mechanical behaviour of the cancellous bone. The experimental and numerical results show the need to take into account the inter and intra-individual variabilities in order to identify the mechanical behaviour of the trabecular bone. If the relative density could explain the mechanical dispersions observed, the relationship established could not explain the different behaviour observed between various loading directions.
{"title":"Influence de l’architecture cellulaire de l’os spongieux sur sa réponse mécanique","authors":"Julien Halgrin, F. Chaari, Eric Markiewicz, P. Drazetic","doi":"10.1051/MECA/2010036","DOIUrl":"https://doi.org/10.1051/MECA/2010036","url":null,"abstract":"Car manufacturers use virtual human models in order to ensure the passengers safety during crash events. To improve the bio-fidelity of these models, we propose to identify the mechanical behaviour of bone tissues, and more particularly of the cancellous bone. After scanning cancellous bone samples with micro computed tomography, compression tests have been performed. The inter and intra-individual variabilities have been studied in order to minimise the results dispersions. Numerical models (taking into account the real architecture of this tissue) have been generated from the data coming from μCT in order to study the effects of architectural parameters on the mechanical behaviour of the cancellous bone. The experimental and numerical results show the need to take into account the inter and intra-individual variabilities in order to identify the mechanical behaviour of the trabecular bone. If the relative density could explain the mechanical dispersions observed, the relationship established could not explain the different behaviour observed between various loading directions.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"19 1","pages":"203-208"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75363315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To apply multi-objective optimization algorithms to highly time expensive metal forming applications, the coupling of the NSGA-II genetic algorithm proposed by Deb with metamodels based on the Meshless Finite Difference Method (MFDM) proposed by Liszka and Orkisz is investigated. The importance of iteratively improving the metamodel during the optimization iterations is highlighted, as well as the capability to accurately determine the Pareto optimal fronts of the studied problems within less than hundred calculations.
{"title":"Optimisation multi-objectifs à base de métamodèle pour des applications en mise en forme des métaux","authors":"Mohsen Ejday, Lionel Fourment","doi":"10.1051/MECA/2010040","DOIUrl":"https://doi.org/10.1051/MECA/2010040","url":null,"abstract":"To apply multi-objective optimization algorithms to highly time expensive metal forming applications, the coupling of the NSGA-II genetic algorithm proposed by Deb with metamodels based on the Meshless Finite Difference Method (MFDM) proposed by Liszka and Orkisz is investigated. The importance of iteratively improving the metamodel during the optimization iterations is highlighted, as well as the capability to accurately determine the Pareto optimal fronts of the studied problems within less than hundred calculations.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"15 1","pages":"223-233"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76051997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Adil El Baroudi, F. Razafimahery, Lalaonirina Rakotomanana-Ravelonarivo
Ce travail a pour but d'etudier le comportement dynamique d'un probleme d'inter-action fluide-structure. Pour cela, on utilise une methode semi-analytique basee sur la projection modale. Les resultats obtenus seront compares avec une solution numerique, obtenue a l'aide du logiciel Comsol Multiphysics. Le probleme etudie est celui issu d'un dispositif experimental developpe en [6]. On calcule certains parametres dynamiques locaux et globaux afin de quantifier la severite d'un choc.
{"title":"Analyse dynamique par projection modale d’un modèle 2D du système couplé crâne-LCR-cerveau","authors":"Adil El Baroudi, F. Razafimahery, Lalaonirina Rakotomanana-Ravelonarivo","doi":"10.1051/MECA/2010061","DOIUrl":"https://doi.org/10.1051/MECA/2010061","url":null,"abstract":"Ce travail a pour but d'etudier le comportement dynamique d'un probleme d'inter-action fluide-structure. Pour cela, on utilise une methode semi-analytique basee sur la projection modale. Les resultats obtenus seront compares avec une solution numerique, obtenue a l'aide du logiciel Comsol Multiphysics. Le probleme etudie est celui issu d'un dispositif experimental developpe en [6]. On calcule certains parametres dynamiques locaux et globaux afin de quantifier la severite d'un choc.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"224 1","pages":"235-243"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85965216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper aims at the formulation of a computational model for the simulation of adhesion phenomena in micro-electro-mechanical systems (MEMS) under various environmental conditions. The present approach is based on finite-element (FE) simulations of a representative part of the surface. The micro-scale analyses include the contact behaviour of the asperities and different "proximity interactions" like Van der Waals and capillary forces. The model is first validated in the simple case of a sphere over a flat surface and then applied to a realistic surface sample.
{"title":"Multiscale finite-element models for predicting spontaneous adhesion in MEMS","authors":"R. Ardito, A. Corigliano, A. Frangi","doi":"10.1051/MECA/2010028","DOIUrl":"https://doi.org/10.1051/MECA/2010028","url":null,"abstract":"This paper aims at the formulation of a computational model for the simulation of adhesion phenomena in micro-electro-mechanical systems (MEMS) under various environmental conditions. The present approach is based on finite-element (FE) simulations of a representative part of the surface. The micro-scale analyses include the contact behaviour of the asperities and different \"proximity interactions\" like Van der Waals and capillary forces. The model is first validated in the simple case of a sphere over a flat surface and then applied to a realistic surface sample.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"65 1","pages":"177-182"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91380701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The simulation of simultaneous diffusion and precipitation of a chemical element during internal oxidation phenomena is presented here, from X-FEM method. This technique seems to be really appropriate when solubility products are very low, or even almost null. In this case, a precipitation front appears and should be properly represented by the numerical simulation. The X-FEM method is then of strong interest, since it allows to know precisely the position of the front all the time of simulation, without remeshing.
{"title":"1D modelling of internal oxidation phenomena with X-FEM","authors":"E. Feulvarch, J. Roux, J. Bergheau","doi":"10.1051/MECA/2010033","DOIUrl":"https://doi.org/10.1051/MECA/2010033","url":null,"abstract":"The simulation of simultaneous diffusion and precipitation of a chemical element during internal oxidation phenomena is presented here, from X-FEM method. This technique seems to be really appropriate when solubility products are very low, or even almost null. In this case, a precipitation front appears and should be properly represented by the numerical simulation. The X-FEM method is then of strong interest, since it allows to know precisely the position of the front all the time of simulation, without remeshing.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"115 21 1","pages":"245-248"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84207706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We discuss, in this paper, a common flux-free method for the computation of strict error bounds for linear and nonlinear finite-element computations. In the linear case, the error bounds are on the energy norm of the error, while, in the nonlinear case, the concept of error in constitutive relation is used. In both cases, the error bounds are strict in the sense that they refer to the exact solution of the continuous equations, rather than to some FE computation over a refined mesh. For both linear and nonlinear solid mechanics, this method is based on the computation of a statically admissible stress field, which is performed as a series of local problems on patches of elements. There is no requirement to solve a previous problem of flux equilibration globally, as happens with other methods.
{"title":"Strict error bounds for linear and nonlinear solid mechanics problems using a patch-based flux-free method","authors":"R. Cottereau, L. Chamoin, P. Díez","doi":"10.1051/MECA/2010049","DOIUrl":"https://doi.org/10.1051/MECA/2010049","url":null,"abstract":"We discuss, in this paper, a common flux-free method for the computation of strict error bounds for linear and nonlinear finite-element computations. In the linear case, the error bounds are on the energy norm of the error, while, in the nonlinear case, the concept of error in constitutive relation is used. In both cases, the error bounds are strict in the sense that they refer to the exact solution of the continuous equations, rather than to some FE computation over a refined mesh. For both linear and nonlinear solid mechanics, this method is based on the computation of a statically admissible stress field, which is performed as a series of local problems on patches of elements. There is no requirement to solve a previous problem of flux equilibration globally, as happens with other methods.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"9 1","pages":"249-254"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86453304","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The power density of a proton exchange membrane fuel cell (PEMFC) depends on several parameters. The contact resistance between the bipolar plate (BPP) and the gas diffusion layer (GDL) and the porosity of the GDL are two main parameters involved in the performance of the PEMFC. The purpose of this work is to develop a numerical model to describe the contact behavior (contact zone, contact force) on the interfaces between the different layers in order to propose an optimal structure for the high performance of PEM fuel cells. Numerical results can help to increase the knowledge of fuel cell's performance and to determine the optimal structure which can be used in the design of fuel cells.
{"title":"Mechanical contact analysis on the interfaces in a proton exchange membrane fuel cell","authors":"Zhiming Zhang, C. Renaud, Zhi-Qiang Feng, H. Yin","doi":"10.1051/MECA/2010039","DOIUrl":"https://doi.org/10.1051/MECA/2010039","url":null,"abstract":"The power density of a proton exchange membrane fuel cell (PEMFC) depends on several parameters. The contact resistance between the bipolar plate (BPP) and the gas diffusion layer (GDL) and the porosity of the GDL are two main parameters involved in the performance of the PEMFC. The purpose of this work is to develop a numerical model to describe the contact behavior (contact zone, contact force) on the interfaces between the different layers in order to propose an optimal structure for the high performance of PEM fuel cells. Numerical results can help to increase the knowledge of fuel cell's performance and to determine the optimal structure which can be used in the design of fuel cells.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"35 1","pages":"183-188"},"PeriodicalIF":0.0,"publicationDate":"2010-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77907742","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：