Claudia Guerra, J. Scheibert, D. Bonamy, Davy Dalmas
Dans les materiaux fragiles, la mecanique lineaire elastique de la rupture (MLER) predit une energie de fracture constante et une vitesse de fissuration limitee par la vitesse de Rayleigh (C R ). Or un grand nombre d’experiences contredisent ces predictions. Pour comprendre ce desaccord, nous avons developpe un dispositif de rupture dynamique dans un materiau fragile modele – le PMMA. Nous montrons l’existence d’une divergence de l’energie de fracture a 0,2 C R due a une transition fragile/quasi-fragile. Nous suggerons qu’un modele geometrique pourra aider a mieux comprendre la dynamique de propagation et d’endommagement.
在脆性材料中，线性弹性断裂力学(MLER)预测恒定的断裂能量和受瑞利速度(rc)限制的开裂速度。许多实验与这些预测相矛盾。为了理解这种差异，我们在一种模型脆性材料——PMMA中开发了一种动态断裂装置。我们证明了由于脆性/准脆性转变，在0.2 C R处存在断裂能量发散。我们认为，几何模型可能有助于更好地理解传播和损伤动力学。
{"title":"Étude expérimentale de la dynamique d’endommagement microscopique accompagnant la rupture dynamique du PMMA","authors":"Claudia Guerra, J. Scheibert, D. Bonamy, Davy Dalmas","doi":"10.1051/MECA/2011116","DOIUrl":"https://doi.org/10.1051/MECA/2011116","url":null,"abstract":"Dans les materiaux fragiles, la mecanique lineaire elastique de la rupture (MLER) predit une energie de fracture constante et une vitesse de fissuration limitee par la vitesse de Rayleigh (C R ). Or un grand nombre d’experiences contredisent ces predictions. Pour comprendre ce desaccord, nous avons developpe un dispositif de rupture dynamique dans un materiau fragile modele – le PMMA. Nous montrons l’existence d’une divergence de l’energie de fracture a 0,2 C R due a une transition fragile/quasi-fragile. Nous suggerons qu’un modele geometrique pourra aider a mieux comprendre la dynamique de propagation et d’endommagement.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"8 1","pages":"205-208"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73419664","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}
Ilias Mouallif, Abdelkrim Chouaf, A. Amri, A. Benali
L’assemblage des rails de chemin de fer se fait generalement a travers un procede de soudage par aluminothermie. Ce procede consiste en la coulee de metal de jonction entre les deux extremites de rails a assembler. La qualite de cet assemblage depend etroitement des conditions de la realisation qui sont generalement difficiles a respecter. En effet, les techniques classiques de controle des rails, mettent souvent, en evidence la presence des defauts de soudure dans la jonction. Selon les observations, ces defauts peuvent etre classes en deux types : defauts d’adhesion (ou defauts de collage) et defauts de porosite (ou defauts de soufflures multiples). Chacun de ces defauts, peut constituer un site privilegie de concentration des contraintes. Selon le niveau de ces contraintes, des eventuels processus d’endommagement risquent de se developper et mettant le rail hors service. Il semble donc necessaire de modeliser le comportement mecanique de ces soudures avec ces defauts en vue de les classer par leur criticite. Dans cette etude, nous avons donc modelise avec un meme chargement et avec les memes conditions aux limites, la jonction de soudure pour chaque type de defaut. Les resultats obtenus sont tres concluants et permettent de bien orienter l’approfondissement de notre analyse cote parametres de soudage.
{"title":"Effets des défauts de soudure aluminothermique sur le comportement mécanique des rails","authors":"Ilias Mouallif, Abdelkrim Chouaf, A. Amri, A. Benali","doi":"10.1051/MECA/2011119","DOIUrl":"https://doi.org/10.1051/MECA/2011119","url":null,"abstract":"L’assemblage des rails de chemin de fer se fait generalement a travers un procede de soudage par aluminothermie. Ce procede consiste en la coulee de metal de jonction entre les deux extremites de rails a assembler. La qualite de cet assemblage depend etroitement des conditions de la realisation qui sont generalement difficiles a respecter. En effet, les techniques classiques de controle des rails, mettent souvent, en evidence la presence des defauts de soudure dans la jonction. Selon les observations, ces defauts peuvent etre classes en deux types : defauts d’adhesion (ou defauts de collage) et defauts de porosite (ou defauts de soufflures multiples). Chacun de ces defauts, peut constituer un site privilegie de concentration des contraintes. Selon le niveau de ces contraintes, des eventuels processus d’endommagement risquent de se developper et mettant le rail hors service. Il semble donc necessaire de modeliser le comportement mecanique de ces soudures avec ces defauts en vue de les classer par leur criticite. Dans cette etude, nous avons donc modelise avec un meme chargement et avec les memes conditions aux limites, la jonction de soudure pour chaque type de defaut. Les resultats obtenus sont tres concluants et permettent de bien orienter l’approfondissement de notre analyse cote parametres de soudage.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"75 12","pages":"343-351"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1051/MECA/2011119","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72371300","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 study presents a new simple lumped model for analyzing the thermally induced seizure of fully lubricated eccentric circumferential groove journal bearings (CGJB). The model represents a significant upgrade of a previous seizure lumped model developed by Pascovici & Kucinschi, in 2002. Main upgrades consist of: eccentric operation, introduction of hydrodynamic lubricant flow rate component, and evaluation of friction power losses based on the short bearing theory with Barwell’s hypothesis on the divergent zone. The viscosity–temperature variation is replaced with Tipei’s viscosity-clearance relationship, as in the previous model. The decrease of viscosity, as a consequence of temperature increase, does not always limit clearance loss, and the seizure process ends with a concentric journal-bushing merged system. Although CGJB’s are less sensitive to this seizure mechanism, the threat still exists and must be avoided. As a result, bearing designers and users should check whether if several safe-operation criteria are met. A recent Institute Pprime experiment on CGJB’s provided a base set of operating parameters, from which numerical simulations have been performed to determine in what conditions the CGJB fails, under thermally induced seizure.
{"title":"Clearance and lubricant selection for avoiding seizure in a circumferential groove journal bearing based on a lumped model analysis","authors":"Alex-Florian Cristea, M. Pascovici, M. Fillon","doi":"10.1051/MECA/2011135","DOIUrl":"https://doi.org/10.1051/MECA/2011135","url":null,"abstract":"This study presents a new simple lumped model for analyzing the thermally induced seizure of fully lubricated eccentric circumferential groove journal bearings (CGJB). The model represents a significant upgrade of a previous seizure lumped model developed by Pascovici & Kucinschi, in 2002. Main upgrades consist of: eccentric operation, introduction of hydrodynamic lubricant flow rate component, and evaluation of friction power losses based on the short bearing theory with Barwell’s hypothesis on the divergent zone. The viscosity–temperature variation is replaced with Tipei’s viscosity-clearance relationship, as in the previous model. The decrease of viscosity, as a consequence of temperature increase, does not always limit clearance loss, and the seizure process ends with a concentric journal-bushing merged system. Although CGJB’s are less sensitive to this seizure mechanism, the threat still exists and must be avoided. As a result, bearing designers and users should check whether if several safe-operation criteria are met. A recent Institute Pprime experiment on CGJB’s provided a base set of operating parameters, from which numerical simulations have been performed to determine in what conditions the CGJB fails, under thermally induced seizure.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"32 1","pages":"399-408"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74880940","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 presents thermohydrodynamic solutions for a finite-width journal bearing with single axial groove on the crown by considering turbulent effects in lubricant film. Appropriate governing equations and boundary conditions are used for the fluid flow and heat transfer process occurring in finite full journal bearings. A general computer program is developed to numerically solve the set of governing equations. Results are provided for THD characteristics of journal bearing in terms of Reynolds number, clearance ratio and eccentricity ratio. Good agreement with published experimental results was achieved. The results indicate that the bearing temperature field and pressure field are considerably influenced by the journal bearing parameters.
{"title":"Thermohydrodynamic behaviors of finite journal bearings with cavitation","authors":"A. A. Solghar, S. G. Nassab","doi":"10.1051/MECA/2011002","DOIUrl":"https://doi.org/10.1051/MECA/2011002","url":null,"abstract":"This paper presents thermohydrodynamic solutions for a finite-width journal bearing with single axial groove on the crown by considering turbulent effects in lubricant film. Appropriate governing equations and boundary conditions are used for the fluid flow and heat transfer process occurring in finite full journal bearings. A general computer program is developed to numerically solve the set of governing equations. Results are provided for THD characteristics of journal bearing in terms of Reynolds number, clearance ratio and eccentricity ratio. Good agreement with published experimental results was achieved. The results indicate that the bearing temperature field and pressure field are considerably influenced by the journal bearing parameters.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"11 1","pages":"5-15"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86610897","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}
Henri-François Boyer, Jeremy Waremme, Jean-Luc Bourdiol, D. Delaunay
This paper deals with a balance of energy and cutting fluid consumption used to manufacture an aluminum clutch case (AlSi9Cu3(Fe)) in industrial context. To establish this balance sheet constitutes the first stage of a reflection aiming at reducing the economic and ecological impact of the production of mechanical parts. Indeed, before intending to set up new technologies susceptible to reduce the cost of manufacturing of a part it is necessary to draw up an inventory of fixtures of the current situation. This paper brings to light the energy and environmental cost connected to the use of cutting fluids in machining. It establishes a prerequisite in the studies necessary for the implementation of a new technology (the minimum quantity lubrication or MQL) and in the characterization of this technology in comparison with the existing (wet machining). This study joins within the framework of a project supported by the “agence de l’environnement et de la matrise de l’energie” (ADEME, France).
{"title":"A study about energy consumption and cutting fluid used to clutch case machining","authors":"Henri-François Boyer, Jeremy Waremme, Jean-Luc Bourdiol, D. Delaunay","doi":"10.1051/MECA/2011133","DOIUrl":"https://doi.org/10.1051/MECA/2011133","url":null,"abstract":"This paper deals with a balance of energy and cutting fluid consumption used to manufacture an aluminum clutch case (AlSi9Cu3(Fe)) in industrial context. To establish this balance sheet constitutes the first stage of a reflection aiming at reducing the economic and ecological impact of the production of mechanical parts. Indeed, before intending to set up new technologies susceptible to reduce the cost of manufacturing of a part it is necessary to draw up an inventory of fixtures of the current situation. This paper brings to light the energy and environmental cost connected to the use of cutting fluids in machining. It establishes a prerequisite in the studies necessary for the implementation of a new technology (the minimum quantity lubrication or MQL) and in the characterization of this technology in comparison with the existing (wet machining). This study joins within the framework of a project supported by the “agence de l’environnement et de la matrise de l’energie” (ADEME, France).","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"59 1","pages":"389-393"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87056041","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 paper concerns the transient thermal behavior of a conrod bearing in an automotive engine subjected to various running conditions. The thermal model is oil shear and contact friction heat generation components. The first part of the paper covers some of the industrial and scientific aspects related to bearings seizure, and emphasizes the importance of removing this failure mechanism as early as the incipient development stages of new automotive engines. The second part concerns several of the broad array of factors that approximate a seizure mechanism. In the third and final part, the mathematical model for conrod bearings seizure is revealed. The objective of the paper is to confirm the conrod seizure model’s utility, complementary with more refined approaches such as the thermo-elasto-hydrodynamic approach.
{"title":"Modeling and prediction of a simplified seizure mechanism occurring in conrod bearings","authors":"J. Ligier, Laurent Dutfoy","doi":"10.1051/MECA/2011101","DOIUrl":"https://doi.org/10.1051/MECA/2011101","url":null,"abstract":"The paper concerns the transient thermal behavior of a conrod bearing in an automotive engine subjected to various running conditions. The thermal model is oil shear and contact friction heat generation components. The first part of the paper covers some of the industrial and scientific aspects related to bearings seizure, and emphasizes the importance of removing this failure mechanism as early as the incipient development stages of new automotive engines. The second part concerns several of the broad array of factors that approximate a seizure mechanism. In the third and final part, the mathematical model for conrod bearings seizure is revealed. The objective of the paper is to confirm the conrod seizure model’s utility, complementary with more refined approaches such as the thermo-elasto-hydrodynamic approach.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"1 1","pages":"265-273"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89231849","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 present paper is concerned with the thermoelectric behaviour of CFRP composite samples subjected to DC currents in view of developing experimental and modelling tools for the characterisation of the thermo-electro-mechanical behaviour of composite materials for aircraft applications. DC currents up to 8 A are injected through the specimens end sides by employing several different electrode techniques whose performances are assessed and compared. Sample and electrode contact resistances are measured for different values of the injected current. The transient and permanent temperatures fields promoted by the injected currents are experimentally measured by infrared thermography. The temperature fields are simulated numerically by a thermoelectric coupled model employing the ABAQUS ® FE commercial code; temperatures can be also approximately calculated by a simple lumped parameter model discarding thermal conduction. The comparison between simulations by the models and measurements allows employing the simplified model as a tool to design thermo-electro-mechanical tests.
{"title":"Development of experimental and modelling tools for the characterisation of the thermo-electro-mechanical behaviour of composite materials for aircraft applications","authors":"M. Gigliotti, M. Lafarie-Frenot, J. Grandidier","doi":"10.1051/MECA/2011012","DOIUrl":"https://doi.org/10.1051/MECA/2011012","url":null,"abstract":"The present paper is concerned with the thermoelectric behaviour of CFRP composite samples subjected to DC currents in view of developing experimental and modelling tools for the characterisation of the thermo-electro-mechanical behaviour of composite materials for aircraft applications. DC currents up to 8 A are injected through the specimens end sides by employing several different electrode techniques whose performances are assessed and compared. Sample and electrode contact resistances are measured for different values of the injected current. The transient and permanent temperatures fields promoted by the injected currents are experimentally measured by infrared thermography. The temperature fields are simulated numerically by a thermoelectric coupled model employing the ABAQUS ® FE commercial code; temperatures can be also approximately calculated by a simple lumped parameter model discarding thermal conduction. The comparison between simulations by the models and measurements allows employing the simplified model as a tool to design thermo-electro-mechanical tests.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"44 1","pages":"87-101"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82763077","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}
Zied Driss, Ghazi Bouzgarrou, Hédi Kchaou, M. Abid
Dans cet article, une etude comparative entre les caracteristiques hydrodynamiques de l’ecoulement laminaire genere en cuves agitees par differents mobiles de proximite de type mono et double vis avec profils simple et modifie a ete menee en utilisant la simulation numerique. Cette etude a ete abordee a l’aide d’un code specifique de dynamique des fluides numerique (CFD), base sur la resolution des equations de Navier-Stokes par la methode des volumes finis. Les resultats numeriques obtenus montrent bien l’influence de la forme du mobile d’agitation sur le comportement de l’ecoulement au sein de la cuve. En effet, on remarque que l’utilisation d’une vis a profil modifie favorise un champ de vitesse plus actif que dans le cas des configurations a profil simple. Par ailleurs, et dans le cas d’une double vis, on note que l’effet de la dissipation visqueuse et du pompage est nettement plus preponderant, presentant ainsi une meilleure efficacite de pompage et de consommation energetique. La comparaison de nos resultats numeriques avec les resultats experimentaux tires de la litterature montre une bonne adequation, ce qui prouve la validite de la methode d’analyse adoptee.
{"title":"Simulation numérique de l’écoulement laminaire induit dans des cuves agitées générées par les mobiles de proximité de type mono et double vis à profils simple et modifié","authors":"Zied Driss, Ghazi Bouzgarrou, Hédi Kchaou, M. Abid","doi":"10.1051/MECA/2011011","DOIUrl":"https://doi.org/10.1051/MECA/2011011","url":null,"abstract":"Dans cet article, une etude comparative entre les caracteristiques hydrodynamiques de l’ecoulement laminaire genere en cuves agitees par differents mobiles de proximite de type mono et double vis avec profils simple et modifie a ete menee en utilisant la simulation numerique. Cette etude a ete abordee a l’aide d’un code specifique de dynamique des fluides numerique (CFD), base sur la resolution des equations de Navier-Stokes par la methode des volumes finis. Les resultats numeriques obtenus montrent bien l’influence de la forme du mobile d’agitation sur le comportement de l’ecoulement au sein de la cuve. En effet, on remarque que l’utilisation d’une vis a profil modifie favorise un champ de vitesse plus actif que dans le cas des configurations a profil simple. Par ailleurs, et dans le cas d’une double vis, on note que l’effet de la dissipation visqueuse et du pompage est nettement plus preponderant, presentant ainsi une meilleure efficacite de pompage et de consommation energetique. La comparaison de nos resultats numeriques avec les resultats experimentaux tires de la litterature montre une bonne adequation, ce qui prouve la validite de la methode d’analyse adoptee.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"17 1","pages":"109-121"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79058295","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}
Une analyse du comportement en fatigue multiaxiale a grand nombre de cycles est conduite a travers la simulation numerique d’agregats polycristallins. Le materiau metallique choisi est un cuivre de microstructure CFC. Le VER, constitue d’un ensemble de 300 grains d’orientation aleatoire equiprobable et de geometrie equiaxe, est sollicite au niveau de la limite de fatigue definie pour un nombre de cycles de 107 cycles, le but etant de calculer les quantites mecaniques relatives a l’echelle mesoscopique (moyenne a l’echelle du grain) apres stabilisation du comportement cyclique local. Les resultats de la simulation montrent la grande dispersion des variables mecaniques a cette echelle mesoscopique. Une analyse statistique de la reponse de l’agregat est proposee pour differents chargements purement alternes : traction, torsion, traction-torsion combinees en-phase. Grâce a la connaissance des quantites mecaniques locales pour un nombre suffisamment grand de microstructures differentes, une analyse critique de certains criteres d’endurance multiaxiaux (Crossland et Dang Van) est conduite.
{"title":"Étude numérique du comportement en fatigue à grand nombre de cycles d’agrégats polycristallins de cuivre","authors":"C. Robert, N. Saintier, T. Palin-Luc, F. Morel","doi":"10.1051/MECA/2011109","DOIUrl":"https://doi.org/10.1051/MECA/2011109","url":null,"abstract":"Une analyse du comportement en fatigue multiaxiale a grand nombre de cycles est conduite a travers la simulation numerique d’agregats polycristallins. Le materiau metallique choisi est un cuivre de microstructure CFC. Le VER, constitue d’un ensemble de 300 grains d’orientation aleatoire equiprobable et de geometrie equiaxe, est sollicite au niveau de la limite de fatigue definie pour un nombre de cycles de 107 cycles, le but etant de calculer les quantites mecaniques relatives a l’echelle mesoscopique (moyenne a l’echelle du grain) apres stabilisation du comportement cyclique local. Les resultats de la simulation montrent la grande dispersion des variables mecaniques a cette echelle mesoscopique. Une analyse statistique de la reponse de l’agregat est proposee pour differents chargements purement alternes : traction, torsion, traction-torsion combinees en-phase. Grâce a la connaissance des quantites mecaniques locales pour un nombre suffisamment grand de microstructures differentes, une analyse critique de certains criteres d’endurance multiaxiaux (Crossland et Dang Van) est conduite.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"299302 1","pages":"209-214"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77876865","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}
Nous etudions experimentalement la dynamique de mousses elastiques (mousse ouverte flexible en polyurethane) plongees dans un fluide visqueux. La mousse est initialement comprimee dans une direction puis brutalement relâchee. Le champ de vitesse de la mousse et la pression du fluide interstitiel (pression de pore) sont mesures au cours de la decompaction du systeme. Pour des petites compactions initiales, on observe que la mousse relaxe exponentiellement vers son etat d’equilibre, avec une dynamique diffusive en accord quantitatif avec les theories classiques de consolidation des sols. En revanche, pour des grandes compactions initiales, la dynamique de relaxation est inhomogene et se deroule a travers un front de decompaction. Un modele diphasique simple permet de predire semi-quantitativement les observations et relie l’existence du front au caractere fortement non-lineaire de la reponse mecanique de la mousse.
{"title":"Dynamique de mousses poroélastiques","authors":"Benjamin Sobac, M. Colombani, Yoël Forterre","doi":"10.1051/MECA/2011115","DOIUrl":"https://doi.org/10.1051/MECA/2011115","url":null,"abstract":"Nous etudions experimentalement la dynamique de mousses elastiques (mousse ouverte flexible en polyurethane) plongees dans un fluide visqueux. La mousse est initialement comprimee dans une direction puis brutalement relâchee. Le champ de vitesse de la mousse et la pression du fluide interstitiel (pression de pore) sont mesures au cours de la decompaction du systeme. Pour des petites compactions initiales, on observe que la mousse relaxe exponentiellement vers son etat d’equilibre, avec une dynamique diffusive en accord quantitatif avec les theories classiques de consolidation des sols. En revanche, pour des grandes compactions initiales, la dynamique de relaxation est inhomogene et se deroule a travers un front de decompaction. Un modele diphasique simple permet de predire semi-quantitativement les observations et relie l’existence du front au caractere fortement non-lineaire de la reponse mecanique de la mousse.","PeriodicalId":49847,"journal":{"name":"Mecanique & Industries","volume":"62 1","pages":"231-238"},"PeriodicalIF":0.0,"publicationDate":"2011-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81353003","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}
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