Publications

2003

• Transmissibilité vibratoire d'un matériau de recyclage
  
  • Luong M. P.
  • Eytard J. C.
  • Khay M.
  • Vinceslas G.
  • Papachristou D.
  , 2003, pp.349-356 (tome 1). No abstract provided
• Safety of salt caverns used for underground storage. Blow out ; mechanical instability ; seepage ; cavern abandonment
  
  • Bérest Pierre
  • Brouard Benoît
  Oil & Gas Science and Technology - Revue d'IFP Energies nouvelles, Institut Français du Pétrole (IFP), 2003, 58, pp.361-384. Thousands of salt caverns (100 in France alone) are being used to store hydrocarbons. This is the safest way to store large quantities of hydrocarbons: salt formations are almost perfectly impermeable, and fire or explosion is impossible underground. However, a small number of accidents (blow-out, product seepage, cavern instability) have occurred in the past. Cavern abandonment is also a concern in some cases. This paper describes several accidents and the lessons that have been drawn from them, leading to considerable improvements in storage design and operation. (10.2516/ogst:2003023)
  DOI : 10.2516/ogst:2003023
• Simulation of stage I fatigue crack gowth in a polycrystal through coupled FEM and discrete dislocation dynamics
  
  • Bertolino Graciela
  • Doquet Véronique
  • Sauzay Maxime
  , 2003. An attempt to model the variability of short crack development in high-cycle fatigue is made by coupling finite element computations of the stresses ahead of a microcrack in a polycrystal with simulations of crack growth along slip planes based on discrete dislocations dynamics. The model predicts a large scatter in growth rates related to the crystallographic disorientations along the crack path. It also describes qualitatively the influence of the mean grain size and the fact that overloads may suppress the endurance limit by allowing arrested cracks to cross the grain boundaries.
• Mobility of lattice defects: discrete and continuum approaches
  
  • Kresse Olga
  • Truskinovsky Lev
  Journal of the Mechanics and Physics of Solids, Elsevier, 2003, 51, pp.1305-1332. In this paper, we study a highly idealized model of a moving lattice defect allowing for an explicit, “first principles” computation of a functional relation between the macroscopic configurational force and the velocity of the defect. The discrete model is purely conservative and contains information only about elasticities of the constitutive elements. The apparent dissipation is due to the presence of microinstabilities and the nonlinearity-induced tunneling of the energy from long to short wavelengths. This type of “radiative damping” is believed to be generic and accounting for a considerable fraction of inelastic irreversibility associated with fracture, plasticity and phase transitions. The paper contains direct comparison of the exact lattice solution with various continuum and quasicontinuum approximations. Despite its simplicity, the model can be used directly for the description of dynamic phase transitions in thin films. (10.1016/S0022-5096(03)00019-X)
  DOI : 10.1016/S0022-5096(03)00019-X
• Activation of diffuse discontinuities and folding of sedimentary layers
  
  • Guiton Martin
  • Leroy Yves
  • Sassi William
  Journal of Geophysical Research : Solid Earth, American Geophysical Union, 2003, 108 (B4), pp.1-20. Folding of sedimentary layers is often accommodated by the opening or sliding of inherited and new discontinuities which are assumed here to be diffuse so that a continuum description applies at the fold scale. The rock rheology is then described with an elastoplasticity model for which the permanent deformation is of simple shear (sliding) or dilation (opening) with respect to specific orientations of the new or inherited diffuse discontinuities. To illustrate the relation between folding and activation of diffuse discontinuities, a three-dimensional layer under compression in the two horizontal directions and sustaining the overburden lithostatic pressure is studied. Cylindrical buckling occurs either before (elastic) or after the diffuse discontinuities have been activated. If buckling is elastic, inherited vertical discontinuities, striking obliquely to the fold geometrical axes, are activated in a sliding mode in the outer arc, leading to a rotation of the principal stress directions. Opening is then detected across new vertical planes striking obliquely to the fold axis. The activation of inherited or new vertical discontinuities can be suppressed if sliding takes place along weak bedding interfaces. Alternatively, early and homogeneous layer-parallel shortening, marked by a reverse fault mode, drastically reduces the critical buckling load compared to the Euler load and modifies the final geometry of buckling which is then more of a circular dome shape. The switching in buckling mode results in the fold limbs in a change from the early reverse fault to a strike-slip fault sliding and to opening across diffuse planes oriented consistently with the final circular structure. (10.1029/2002JB001770)
  DOI : 10.1029/2002JB001770
• A computational basis for elastodynamic cavity identification in a semi-infinite solid
  
  • Nintcheu Fata Sylvain
  • Guzina Bojan B
  • Bonnet Marc
  Computational Mechanics, Springer Verlag, 2003, 32, pp.370-380. The focus of this paper is a computational platform for the non-intrusive, active seismic imaging of subterranean openings by means of an elastodynamic boundary integral equation (BIE) method. On simulating the ground response to steady-state seismic excitation as that of a uniform, semi-infinite elastic solid, solution to the 3D inverse scattering problem is contrived as a task of minimizing the misfit between experimental observations and BIE predictions of the surface ground motion. The forward elastodynamic solution revolves around the use of the half-space Greenrsquos functions, which analytically incorporate the traction-free boundary condition at the ground surface and thus allow the discretization and imaging effort to be focused on the surface of a hidden cavity. For a rigorous approach to the gradient-based minimization employed to resolve the cavity, sensitivities of the trial boundary element model with respect to (geometric) void parameters are evaluated using an adjoint field approach. Details of the computational treatment, including the regularized (i.e. Cauchy principal value-free) boundary integral equations for the primary and adjoint problem, the necessary evaluation of surface displacement gradients and their implementation into a parallel code, are highlighted. Through a suite of numerical examples involving the identification of an ellipsoidal cavity, a parametric study is presented which illustrates the importance of several key parameters on the imaging procedure including the prior information, ldquomeasurementrdquo noise, and the amount of experimental input. (10.1007/s00466-003-0494-4)
  DOI : 10.1007/s00466-003-0494-4
• Crystallographic fatigue crack growth in a polycrystal: simulations based on FEM and discrete dislocation dynamics
  
  • Bertolino Graciela
  • Doquet Véronique
  • Sauzay Maxime
  , 2003. An attempt to model the variability of short cracks development in high-cycle fatigue is made by coupling finite element calculations of the stresses ahead of a microcrack in a polycrystal with simulations of crack growth along slip planes based on discrete dislocations dynamics. The model predicts a large scatter in growth rates related to the roughness of the crack path. It also describes the influence of the mean grain size and the fact that overloads may suppress the endurance limit by allowing arrested cracks to cross the grain boundaries.
• Etude micromécanique de la disparition du seuil de fissuration par fatigue dans un alliage de titane biphasé à fort K_max
  
  • Mignot Frédéric
  • Doquet Véronique
  • Sarrazin-Baudoux Christine
  • Petit Jean
  Journal de Physique IV Proceedings, EDP Sciences, 2003, 106, pp.33-42. L'alliage Ti6246 présente, lors d'essais de fissuration par fatigue à K_max constant et ΔK décroissant un comportement atypique : lorsque K_max> 0.7K_IC, on observe, sous air comme sous vide, au lieu du seuil attendu, un régime de propagation à vitesse constante, dix fois plus élevée à l'ambiante qu'à 500°C. Le fluage, qui se manifeste dès l'ambiante dans cet alliage semble jouer un rôle dans ce phénomène. Toutefois, des analyses par spectrométrie de masse d'ions secondaires font apparaître une sur-concentration en hydrogène au voisinage d'une fissure développée dans le régime anormal. Des essais de fissuration, traction et fluage sont donc entrepris sur le matériau brut, appauvri ou enrichi en hydrogène, pour partie dans la chambre d'un microscope électronique à balayage, dans le but d'explorer ce phénomène. On constate qu'un enrichissement en hydrogène augmente la ductilité du matériau et sa tendance au fluage à l'ambiante et un enrichissement plus prononcé la diminue. (10.1051/jp4:20030213)
  DOI : 10.1051/jp4:20030213
• Testing with SHPB from quasi-static to dynamic strain rates
  
  • Othman Ramzi
  • Bussac Marie-Noëlle
  • Collet Pierre
  • Gary Gérard
  , 2003, 110, pp.397-404. We have developed a new method for separating dispersive waves in elastic and viscoelastic rods from three-point strain and one-point velocity measurements. Stress, strain, displacement and velocity, which were supposed to be homogenous in a rod section, were therefore determined at any point ofthe bar. This method is based on the assumption of a one dimensional and single mode dispersive wave propagation. This method was used in the frequency domain and took into account wave dispersion. It was shown to be stable with respect to noise. The measuring time is increased considerably. Subsequently, the maximum strain which can be measured in a material tested with a classical SHPB (Split Hopkinson Pressure Bar) set-up is also increased and is no more limited by the length of the bars. The method was used to evaluate the rate sensitivity ofaluminum honeycomb over a wide range ofstrain-rates (from 10 -2 to 1000 s -1). (10.1051/jp4:20020726)
  DOI : 10.1051/jp4:20020726
• Peierls-Nabarro landscape for martensitic phase transitions
  
  • Truskinowsky Lev
  • Vainchtein Anna
  Physical Review B: Condensed Matter and Materials Physics (1998-2015), American Physical Society, 2003, 67 (17). We consider a prototypical model of a martensitic phase transition, which takes discreteness and nonlocality into account and allows one to reconstruct explicitly the Peierls-Nabarro energy landscape for the phase boundaries. We solve the discrete problem exactly and obtain a simple expression for the critical Peierls force that is necessary to release a lattice-trapped phase boundary. The model suggests specific relations between the microscopic parameters of the lattice and the size of the hysteresis in martensitic materials, which we verify for the cubic-$β'_1$-monoclinic phase transition in Cu-Al-Ni alloy. (10.1103/physrevb.67.172103)
  DOI : 10.1103/physrevb.67.172103
• The treatment of 'pinching locking' in 3D-shell elements
  
  • Chapelle Dominique
  • Ferent Anca
  • Le Tallec Patrick
  ESAIM: Mathematical Modelling and Numerical Analysis, Société de Mathématiques Appliquées et Industrielles (SMAI) / EDP, 2003, 37 (1), pp.143-158. We consider a family of shell finite elements with quadratic displacements across the thickness. These elements are very attractive, but compared to standard general shell elements they face another source of numerical locking in addition to shear and membrane locking. This additional locking phenomenon - that we call ''pinching locking'' - is the subject of this paper and we analyse a numerical strategy designed to overcome this difficulty. Using a model problem in which only this specific source of locking is present, we are able to obtain error estimates independent of the thickness parameter, which shows that pinching locking is effectively treated. This is also confirmed by some numerical experiments of which we give an account. (10.1051/m2an:2003015)
  DOI : 10.1051/m2an:2003015
• A “Numerical Mesoscope” for the Investigation of Local Fields in Rate-Dependent Elastoplastic Materials at Finite Strain
  
  • Haddadi Halim
  • Teodosiu Cristian
  • Héraud S.
  • Allais L.
  • Zaoui André
  , 2001, 108, pp.311-320. We propose a “numerical mesoscope” which could be used for the analysis of the local mechanical fields over small critical areas of microheterogeneous materials, in order to predict the local initiation of specific deformation or damage mechanisms. The subdomain under investigation is embedded in a very large homogeneous matrix obeying the overall behavior of the studied material, as determined experimentally. This matrix is subjected to homogeneous stress or strain boundary conditions and the homogeneous elements of the subdomain and their interfaces are given their known or assumed constitutive behavior. A finite element analysis is then performed on the whole body by making use of different constitutive equations within the subdomain and in the surrounding matrix. The general methodology of this approach is reported and applied to a metallic rate-dependent elastoplastic polycrystal and to microheterogeneous subdomains consisting of given multicrystalline patterns whose grains obey crystalline elastoplastic constitutive equations of Schmid type at finite strain. Application to the intergranular creep damage of a stainless steel shows a good agreement between the largest computed normal stresses on the grain boundaries and the observed debonded boundaries of the actual material. (10.1007/978-94-017-0297-3_28)
  DOI : 10.1007/978-94-017-0297-3_28
• Remarques sur les contraintes résiduelles
  
  • Bérest Pierre
  • Vouille Gérard
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2003, 331 (6), pp.455-460. Les contraintes résiduelles observées dans les solides peuvent résulter de déformations initiales non compatibles. Elles sont alors déterminées, en général, par le tenseur d'incompatibilité du tenseur des déformations initiales. Toutefois, réciproquement, la nullité du tenseur d'incompatibilité ne suffit pas pour conclure à l'absence de contraintes résiduelles, dans le cas où le solide est non simplement connexe, ou présente des surfaces de discontinuité. Plusieurs exemples sont présentés. (10.1016/S1631-0721(03)00090-1)
  DOI : 10.1016/S1631-0721(03)00090-1
• Prise en compte de la rugosité dans le prévision de la tenue en fatigue des roulements
  
  • Thoquenne Guillaume
  • Lubrecht Ton
  • Dang Van Ky
  • Maitournam Habibou
  • Peyrac Catherine
  • Lieurade Henri-Paul
  , 2003.
• Linear stability analysis in fluid-structure interaction with transpiration. Part I: Formulation and mathematical analysis
  
  • Fernández Miguel Angel
  • Le Tallec Patrick
  Computer Methods in Applied Mechanics and Engineering, Elsevier, 2003, 192 (43), pp.4805-4835,. The aim of this work is to provide a new Linearization Principle approach particularly suited for problems in fluid-structure stability. The complexity here, and the main difference with respect to the classical approach, comes from the fact that the full non-linear fluid equations are written in a moving (i.e. time dependent) domain. The underlying idea of our approach uses transpiration techniques [J. Fluid Mech. 4 (1958) 383 ; G. Mortchéléwicz, Application of linearized Euler equations to flutter, in : 85th AGARD SMP Meeting, Aalborg, Denmark, 1997 ; P. Raj, B. Harris, Using surface transpiration with an Euler method for cost-effective aerodynamic analysis, in : AIAA 24th Applied Aerodynamics Conference, number 93-3506, Monterey, Canada, 1993 ; AIAA 27(6) (1989) 777], with the formalization and linearization recently developed in [Rév. Européenne Élém. Finis, 9(6-7) (2000) 681, A. Dervieux (Ed.), Fluid-Structure Interaction, Kogan Page Science, London, 2003 (Chapter 3)]. This allows us to obtain a new grid independent coupled spectral problem involving the linearized Navier-Stokes equations and those of a reduced linear structure. The coupling is realized through specific transpiration conditions acting on a fixed interface, while keeping a fixed fluid domain. We provide a rigorous mathematical treatment of this eigenproblem. We prove that the corresponding eigenmodes, characterizing the free evolution of the system, can be obtained from the characteristic values of a compact operator acting on a Hilbert space. Moreover, we localize the eigenfrequencies of the system in a parabolic region of the complex plan centered along the positive real axis. (10.1016/j.cma.2003.07.001)
  DOI : 10.1016/j.cma.2003.07.001
• Ondes adhérence-glissement-décollement sous contact unilatéral frottant
  
  • Oueslati Abdelbacet
  • Nguyen Quoc Son
  • Baillet Laurent
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2003, 331 (2), pp.133-140. Il s'agit d'une étude numérique sur la réponse dynamique d'un système de deux cylindres coaxiaux, en rotation relative avec contact unilatéral frottant suivant la loi de Coulomb. On complète les résultats semi-analytiques antérieurs obtenus dans Moirot, Nguyen, C. R. Acad. Sci. Paris Sér. IIb 328 (2000) 663–669, sur les ondes adhérence–glissement en simulant par le calcul numérique la transition dynamique du système à partir d'un état initial quelconque vers la propagation d'une onde de surface. Le cas des ondes adhérence–glissement–décollement est examiné. (10.1016/S1631-0721(02)00009-8)
  DOI : 10.1016/S1631-0721(02)00009-8
• Microstructure influence on the damage initiation in unirradiated zirconium alloys
  
  • Elbachiri K.
  • Crépin Jérôme
  • Rebeyrolle V.
  • Bretheau T.
  , 2003. No abstract provided
• Identification de lois de comportement cristallines à partir du couplage EBSD/microextensometrie/Eléments Finis. Application au zirconium grade 702
  
  • Dexet M.
  • Crépin Jérôme
  • Gélébart L.
  , 2003. No abstract provided
• Contribution du fluage à froid et de l'hydrogène à la fissuration anormale du Ti 6246 sous chargement cyclique à fort Kmax
  
  • Doquet V.
  • Mignot F.
  • Sarrazin-Baudoux C.
  , 2003. No abstract provided
• Couplage EBSD - micro-extensométrie et identification de lois cristallines
  
  • Roos A.
  • Hoc T.
  • Gélébart L.
  • Crépin Jérôme
  • Bornert Michel
  • Bretheau T.
  , 2003. No abstract provided
• Génie parasismique : aspects dynamiques et vibratoires en génie civil
  
  • Luong Minh-Phong
  , 2003, pp.3 tomes. Actes du colloque AFPS 2003. Plus de 160 communications ont été présentées, réparties selon les thèmes suivants : - Géosciences (vol. 1) : sismologie générale et aléa déterministe ; mouvements sismiques pour l'ingénieur ; effets de site classiques ; interaction sol-structure et effet de site "urbains" ; géotechnique parasismique (sols, fondations et ouvrages). - Dynamique des structures et conception (vol. 2) : méthodes d'analyse et de modélisation (analyse simplifiée et indicateurs de nocivité, méthodes spécifiques) ; expérimentation ; constructions métalliques ; équipements industriels et structures particulières ; ponts. - Gestion de l'existant et du risque (vol. 3) : diagnostic et renforcement de l'existant ; existant nucléaire ; méthode d'estimation de la vulnérabilité à grande échelle ; scénarios et vulnérabilité urbaine ; aspects socio-économiques ; vers un nouveau zonage sismique de la France. - Benchmark Camus (vol. 3).
• Identification de failles sismiques par une fonctionnelle de réciprocité généralisée
  
  • Bui Huy Duong
  • Constantinescu Andrei
  • Maigre Hubert
  , 2003, 1, pp.13-20.
• Caractérisation de la répartition de la déformation dans les matériaux hétérogènes
  
  • Doumalin Pascal
  • Bornert Michel
  • Crépin Jérôme
  Mechanics & Industry, EDP Sciences, 2003, 4, pp.607-617. On présente une méthode originale de caractérisation de la répartition de la déformation dans les matériaux hétérogènes, basée sur l'adaptation des techniques statistiques de caractérisation morphologique par covariance à 2 points aux champs locaux de déformation mesurés par microextensométrie MEB. Elle permet de montrer que le comportement mécanique n'est pas uniquement la conséquence d'interactions très locales entre grains ou domaines de phases voisins, mais résulte aussi de phénomènes à plus grande portée. (10.1016/j.mecind.2003.09.002)
  DOI : 10.1016/j.mecind.2003.09.002
• Mechanical constraints on the chronology of fracture activation in folded Devonian sandstone of the western Moroccan Anti-Atlas
  
  • Guiton M. L. E.
  • Sassi W.
  • Leroy Y. M.
  • Gauthier B. D. M.
  Journal of Structural Geology, Elsevier, 2003, 25, pp.1317-1330. The three-dimensional meter-scale fracture networks, observed on exposed folds between the towns of Tata and Akka, western Moroccan Anti-Atlas, consist mostly of planar discontinuities, which are sub-perpendicular to the bedding and partitioned in three main sets. The chronology of their activation is proposed in five stages since the Hercynian orogeny. Stage 1 predates folding and involves the horizontal compression of the Emsian sandstone. It involves fracture set I, composed of systematic joints parallel to the direction of compression. Stages 2–4 correspond to the folding and are marked in the outer-arc by the activation of fracture set II, composed mainly of joints parallel to the fold axial plane. Stage 5 is a regional shear event during which sets I and III, separated by an angle close to 60°, are activated in a conjugate manner. To throw light on the recurrent difficulty in discriminating between activation of inherited and new fractures, an elasto-plastic model is used to construct a stress path in the pervasively fractured medium idealized as a continuum. Each fracture set obeys the Mohr–Coulomb criterion truncated in tension to describe both sliding and opening activations. Finite-element simulations of a simple buckling event accounting for the field fracture sets are presented. It is shown that set I cannot be generated by folding and thus does belong to stage 1. Set II is activated at a later stage of folding than expected from the field interpretation. Set III cannot be activated during stage 2, confirming its role in stage 5. The advantages and limitations of the proposed modeling are finally discussed. (10.1016/S0191-8141(02)00155-4)
  DOI : 10.1016/S0191-8141(02)00155-4
• A shakedown analysis in hardening plasticity
  
  • Nguyen Quoc Son
  Journal of the Mechanics and Physics of Solids, Elsevier, 2003, 51, pp.101-125. The extension of classical shakedown theorems for hardening plasticity is interesting from both theoretical and practical aspects of the theory of plasticity. This problem has been much discussed in the literature. In particular, the model of generalized standard materials gives a convenient framework to derive appropriate results for common models of plasticity with strain-hardening. This paper gives a comprehensive presentation of the subject, in particular on general results which can be obtained in this framework. The extension of the static shakedown theorem to hardening plasticity is presented at first. It leads by min-max duality to the definition of dual static and kinematic safety coefficients in hardening plasticity. Dual static and kinematic approaches are discussed for common models of isotropic hardening, of limited or unlimited kinematic hardening. The kinematic approach also suggests for these models the introduction of a relaxed kinematic coefficient following a method due to Koiter. Some models for soils such as the Cam-clay model are discussed in the same spirit for applications in geomechanics. In particular, new appropriate results concerning the variational expressions of the dual kinematic coefficients are obtained. (10.1016/S0022-5096(02)00058-3)
  DOI : 10.1016/S0022-5096(02)00058-3