Publications

2001

• Storage of tritiated water in salt caverns
  
  • Bérest Pierre
  • Brouard Benoit
  , 2001.
• Creep of argillites under small mechanical loading
  
  • Bérest Pierre
  • Charpentier Jean-Pierre
  • Valès Frédéric
  , 2001. Study of rocks under small (typically s = 0.1 MPa) mechanical loading is of great importance both for a better understanding of geological deformation features and for the analysis of rock mass behavior at large distance from underground openings. A very small amount of experimental data is available. Very long-term tests are required, as the creep rates induced by such small mechanical loading are exceedingly small (10 ­13 to 10-12s-1). Accurate displacement measurements and a thorough control of both hygrometry and temperature must be used. We used high resolution displacements sensors, whose resolution is 10-9m, designed for purpose by P.A.Blum from IPG Paris. The creep test system were set in a 20-m deep gallery where hygrometry is close to 100%PHs suburbs ; and in a 200-m deep salt mine where hygrometry is 54+/-2% RH . In both sites daily temperature fluctuations are smaller than a few hundredth of a Celsius degree, allowing for quite constant ambient conditions during several month long tests, the observed displacement-versus-time curves can be corrected from the thermoelastic effects. Creep of salt samples was measured in the 200-m deep mine ; transient creep, steady-state creep and the effcts of stress drop were observed during a 18-month long test. The measured steady-state creep rates (10-12s-1) are much faster than the values extrapolated from standard tests performed under larger mechanical loading. Argillite creep was measured in the 20-m deep gallery. High hygrometry conditions result in relatively fast clay swelling. In this context, argillite creep rate, which is slower than swelling rate by one order of magnitude, is difficult to identify
• Dynamique des systèmes de solides rigides avec liaisons unilatérales ou frottement
  
  • Ballard Patrick
  , 2001.
• A new approach for Hardening Rate Measurements in HCP Materials and Applications in Mechanical Modelling
  
  • Philippe Marie-Jeanne
  • Crépin Jérôme
  • Lecomte J.S.
  , 2001.
• Some aspects of dynamic testing with wave-guides
  
  • Gary G.
  , 2001.
• Intelligent design of woven composites
  
  • Zarka Joseph
  • Doux Thierry
  , 2001. (10.1016/S0167-6636(02)00259-4)
  DOI : 10.1016/S0167-6636(02)00259-4
• Solid-fluid phase transformation within grain boundaries during compaction by pressure solution
  
  • Ghoussoub Joumana
  • Leroy Yves
  Journal of the Mechanics and Physics of Solids, Elsevier, 2001, 49 (10), pp.2385-2430. The overall compaction of porous rocks due to intergranular pressure solution (IPS) results from the dissolution of minerals within contact regions and the diffusive transport through the grain boundary of the dissolved species towards the fluid-filled pore space. The grain boundary structure can be imagined to be composed of dry contact zones, thin fluid films and fluid-filled cavities. The connectiveness and tortuosity of this structure determine the effective diffusivity of grain contacts and thus the potential of porous rock to compact by the action of IPS. The evolution in time of the grain-boundary structure, and thus of the effective diffusivity, is discussed here with the help of two 2D initial- and boundary-value problems which are solved by analytical and numerical means. The evolution of the solid–fluid interfaces within the grain boundary is governed by a phase transformation between the non-hydrostatically stressed elastic solid and the trapped fluid assumed in mechanical equilibrium. The characteristic time is provided by a linear kinetic law. The evolution of the structure away from a state of thermodynamic equilibrium during a loading normal to the grain boundary is found to occur in two steps. The first one consists of a diffuse morphology evolution in time and results in an enhancement of any initial stress concentration. The second step is characterized by a rapid and localized dissolution in the region of stress concentration. The latency period prior to localization is governed by the magnitude of the non-hydrostatic remote stress as well as the microstructural geometric factor responsible for the initial stress concentration at the solid–fluid interface. The localized dissolution is shown to provide a mechanism for the fluid to penetrate a previously dry contact region by marginal dissolution and thus to create a fluid film. However, the newly formed thin fluid layer is found to be unstable pointing to a possible repeated reorganization or dynamic evolution of the grain boundary internal structure during the action of IPS. (10.1016/S0022-5096(01)00012-6)
  DOI : 10.1016/S0022-5096(01)00012-6
• Inductive Logic Programming
  
  • Rouveirol Céline
  • Sebag Michèle
  , 2001, 2157. (10.1007/3-540-44797-0)
  DOI : 10.1007/3-540-44797-0
• Etude thermodynamique de l'évolution sous chargement dynamique de structures délaminées
  
  • Pradeilles-Duval Rachel Marie
  Comptes rendus de l’Académie des sciences. Série IIb, Mécanique, Elsevier, 2001, 329, pp.535-540. On considère un assemblage de plaques modélisant une structure stratifiée se délaminant. La propagation du délaminage est caractérisée par la transformation d'une plaque en deux autres. On examine dans le cadre du formalisme hamiltonien l'influence d'un chargement dynamique sur une telle structure, d'un point de vue thermodynamique. L'étude du taux de restitution associé à la propagation de la fissure, considérée comme une source de chaleur localisée sur le front de délaminage, est discutée. (10.1016/S1620-7742(01)01364-2)
  DOI : 10.1016/S1620-7742(01)01364-2
• Application du contrôle optimal à l'identification d'un chargement thermique
  
  • Delattre Benoît
  • Ivaldi Damien
  • Stolz Claude
  , 2001, 11 (2-4), pp.165-172. La détermination du champ de température sur certaines pièces d'un moteur est obtenue par la résolution d'un problème inverse. Une alternative aux méthodes expérimentales coûteuses utilisées aujourd'hui est la méthode du contrôle optimal qui permet d'estimer le champ de température à partir de quantités mesurées sur pièce. Différents tests préfigurent des possibilités de prédiction et de fiabilité de la méthode. (10.3166/reef.11.393-404)
  DOI : 10.3166/reef.11.393-404
• Action d'une conduite circulaire sur un sol cohérent
  
  • Salençon Jean
  , 2001, 2001-08-31, pp.1311-1314. On s'intéresse à la détermination théorique de la capacité portante d'un sol homogène, isotrope, purement cohérent sur lequel repose une conduite circulaire. Les deux conditions extrêmes de contact à l'interface entre la conduite et le sol (interface lisse sans résistance à la traction et interface totalement adhérente) sont envisagées ce qui permet d'encadrer la solution du problème réel. On a appliqué les méthodes d'approche par l'intérieur statique et d'approche par l'extérieur cinématique de la théorie du calcul à la rupture pour une analyse paramétrique en fonction de la profondeur d'enfoncement de la conduite. Les évaluations par défaut et par excès ainsi obtenues montrent que l'effet de la gravité est purement additif, égal à la simple «poussée d'Archimède» exercée par le sol et améliorent, dans le cas de l'interface lisse, les résultats antérieurs de Mur1l: Wagner & Randolph.
• On the behaviour characterisation of polymeric foams over a large range of strain rates
  
  • Zhao Han
  • Gary Gérard
  , 2001, pp.23-28. The testing and modelling of the mechanical behaviour of some polymeric foams involved in the automotive industry are presented. A variety of current experimental arrangements over a large range of strain rates have been reviewed. Recent improvements of a particularly useful technique for impact loading–the split Hopkinson bar–are presented. A phenomenological model is developed to describe experimental data. Difficulties for 3-dimensional testing and modelling are also discussed.
• Etude de systèmes avec surfaces de discontinuités mobiles sous chargement thermomécanique
  
  • Peigney Michaël
  • Stolz C.
  , 2001. No abstract provided
• Study of the creep behavior of a possible host clayey rock
  
  • Gasc-Barbier M.
  • Chanchole S.
  • Lecampion B.
  • Bérest P.
  • Hoteit N.
  , 2001. No abstract provided
• Fatigue Analysis during One-parametered Loadings
  
  • Zarka Joseph
  • Karaouni Habib
  , 2001.
• Effet de la fréquence et de l'environnement sur la propagation des fissures de fatigue en mode II dans un acier maraging
  
  • Doquet V.
  , 2001. No abstract provided
• Un outil de la mécanique des matériaux : la micro-extensométrie
  
  • Bretheau Thierry
  • Crépin Jérôme
  • Doumalin Pascal
  • Bornert Michel
  , 2001.
• Application du principe du maximum de vraisemblance à la séparation des ondes dans les barres
  
  • Othman Ramzi
  • Bussac Marie-Noëlle
  • Collet Pierre
  • Gary Gérard
  , 2001.
• Techniques of Infrared Thermography
  
  • Luong M. P.
  , 2001, pp.342-357.
• Fatigue Analysis of Welded Structures during Random Loadings
  
  • Zarka Joseph
  • Karaouni Habib
  , 2001.
• Comportement mécanique non linéaire et homogénéisation
  
  • Bornert Michel
  , 2001.
• Life-time prediction of aluminum automotive components under thermo-mechanical cyclic loadings
  
  • Verger Laetitia
  • Charkaluk Eric
  • Constantinescu Andrei
  , 2001.
• Identification of constitutive parameters in engineering problems
  
  • Constantinescu Andrei
  • Lecampion Brice
  • Verger Laetitia
  • Tardieu Nicolas
  , 2001.
• Identification of elastoviscoplastic materials: a discussion about uniqueness
  
  • Constantinescu Andrei
  , 2001.
• Modelling rate-dependent effects in heterogeneous materials
  
  • Masson Renaud
  • Zaoui André
  , 2001.