Publications

2004

• Experimental and numerical rolling contact fatigue study on the 32CrMoV13 steel
  
  • Coelho Luís
  • Mourão Dias Antonio Angelo
  • Lieurade Henri-Paul
  • Maitournam Habibou
  Fatigue and Fracture of Engineering Materials and Structures, Wiley-Blackwell, 2004, 27, pp.811-823. The aim of this work is to study pure rolling contact fatigue in 32CrMoV13 quenching and tempering steel. The study involves both experimental and numerical work. The influence of the roughness and the residual stresses on the mechanisms and zones of cracking were studied. The results show a rapid reduction in roughness during the first minute of test but even so there will be specimen deterioration. The residual stress profile after rolling contact tests have high compression values in the surface and at a depth of approximately 240 μm, which is related with the Hertzian maximal shear stress. The numerical simulation of the Hertzian loading was used both to determine the elastic shakedown of the material and to apply a high‐cycle multiaxial fatigue criterion. The three‐dimensional finite element analysis used in the numerical calculation includes elastic‐linear kinematic hardening plastic material and allows the introduction of an initial residual stress state. Taking into account the elastoplastic load induced by the Hertz pressure, low‐cycle fatigue tests were used to characterize the mechanical properties of the material. In order to validate the numerical simulation, the results of the calculation after elastic shakedown were compared with the values measured by X‐ray diffraction after rolling contact tests. The results showed a reasonable agreement between calculated and measured stresses. The Dang Van high‐cycle multiaxial fatigue criterion showed a good relationship with the experimental findings. (10.1111/j.1460-2695.2004.00797.x)
  DOI : 10.1111/j.1460-2695.2004.00797.x
• Three-dimensional rate-dependent crystal plasticity based on Runge-Kutta algorithms for update and consistent linearization
  
  • Raphanel Jean
  • Ravichandran G.
  • Leroy Y.
  International Journal of Solids and Structures, Elsevier, 2004, 41, pp.5995-6021.
• Problems related to thermal fatigue of stainless steel: interactions of orthogonal cracks networks under biaxial tension and influence of stress biaxiality on 3D mode I crack growth
  
  • Kane A.
  • Doquet V.
  , 2004. No abstract provided
• Abandon des mines de sel: faut-il ennoyer ?
  
  • Bérest Pierre
  • Brouard Benoît
  • Feuga Bernard
  Revue française de Géotechnique, edp sciences, 2004, 106-107, pp.53-71. L’abandon d’une mine de sel sèche soulève un problème très particulier en raison de la forte probabilité que la mine soit noyée après son abandon, avec des conséquences significatives à la surface du sol. On analyse plusieurs cas d’ennoyage survenus pendant que des mines de sel étaient encore actives, afin de comparer les avantages et les inconvénients d’un ennoyage délibéré avant l’abandon, et notamment la dégradation possible des bancs marneux situés au mur de la mine. (10.1051/geotech/2004106053)
  DOI : 10.1051/geotech/2004106053
• Application of a $n$-phase model to the diffusion coefficient of chloride in mortar
  
  • Caré Sabine
  • Hervé E.
  Transport in Porous Media, Springer Verlag, 2004, 56, pp.119-135. The determination of the chloride diffusion coefficient of a concrete is needed to help the prediction of the service life of concrete structure. In this paper, we propose first a critical review of models for chloride diffusion coefficients already used in literature at different scales and then we develop an analytical model, which takes into account the characteristics of the different phases of concrete. These materials are treated as a three-phase composite, consisting of a cement continuous phase, of an aggregates dispersed phase and of an interface transition zone. Chloride diffusion coefficient using an n-layered inclusion-based micromechanical modeling is predicted. The details of calculations are summarized hereafter and experimental measurements obtained on mortars are compared with predicted results. (10.1023/B:TIPM.0000021730.34756.40)
  DOI : 10.1023/B:TIPM.0000021730.34756.40
• Topological derivative for the inverse scattering of elastic waves
  
  • Guzina B. B.
  • Bonnet Marc
  Quarterly Journal of Mechanics and Applied Mathematics, Oxford University Press (OUP), 2004, 57, pp.161-179. To establish an alternative analytical framework for the elastic-wave imaging of underground cavities, the focus of this study is an extension of the concept of topological derivative, rooted in elastostatics and shape optimization, to three-dimensional elastodynamics involving semi-infinite and infinite solids. The main result of the proposed boundary integral approach is a formula for topological derivative, explicit in terms of the elastodynamic fundamental solution, obtained by an asymptotic expansion of the misfit-type cost functional with respect to the creation of an infinitesimal hole in an otherwise intact (semi-infinite or infinite) elastic medium. Valid for an arbitrary shape of the infinitesimal cavity, the formula involves the solution of six canonical exterior elastostatic problems, and becomes fully explicit when the vanishing cavity is spherical. A set of numerical results is included to illustrate the potential of topological derivative as a computationally efficient tool for exposing an approximate cavity topology, location, and shape via a grid-type exploration of the host solid. For a comprehensive solution to three-dimensional inverse scattering problems involving elastic waves, the proposed approach can be used most effectively as a pre-conditioning tool for more refined, albeit computationally intensive minimization-based imaging algorithms. To the authors' knowledge, an application of topological derivative to inverse scattering problems has not been attempted before; the methodology proposed in this paper could also be extended to acoustic problems. (10.1093/qjmam/57.2.161)
  DOI : 10.1093/qjmam/57.2.161
• Quasi-static evolution of delaminated structures: analysis of stability and bifurcation
  
  • Pradeilles-Duval Rachel-Marie
  International Journal of Solids and Structures, Elsevier, 2004, 41, pp.103-130. Within the framework of dissipative systems with time-independent behavior, the study of the evolution of delaminated structures modeled by frames of plates is considered via a global energetic analysis. Assuming the current equilibrium state is known, the governing rate problem for the instantaneous delamination is formulated as either a system of local equations or as a global variational inequality. This global formulation enables to study stability and non-bifurcation of the evolution of a delaminated structure under quasi-static loading, corresponding to the statement of existence and uniqueness criteria for the rate solution. Two analytical applications to simple structures are presented. (10.1016/j.ijsolstr.2003.07.006)
  DOI : 10.1016/j.ijsolstr.2003.07.006
• Parameter Identification of a Crystallographic Constitutive Law Using Local Strain Fields
  
  • Héripré Eva
  • Crépin Jérôme
  • Roos Arjen
  • Gelebart Lionel
  • Chaboche Jean Louis
  , 2004. Polycrystalline Titanium-Aluminides (TiAl) are very interesting materials for the aerospace industry. Their low density, combined with a high Young's modulus, render them prime candidates for industrial applications at temperatures up to 800°C. However, the principal obstacle to widespread utilisation remains their low ductility (around 2%) at room temperature. This limited ductility is the consequence of an early damaging of the microstructure, due to the low number of straining mechanisms involved during the deformation process. This gives rise to strain heterogeneity in the polycrystal, thereby causing incompatibilities and microcracks. The aim of this study is to predict, for macroscopic tests carried out at room temperature, the occurrence and the localization of microcracks directly from the actual microstructure and the straining mechanisms involved. In order to identify the parameters of the crystallographic constitutive law, the experimental strain field, obtained by an imaging correlation technique, has been coupled to finite element simulations carried out at the same scale. The difference between the experimental and calculated strain fields is then minimized using a genetic algorithm.
• Fluage du sel gemme sous très faibles charges
  
  • Bérest Pierre
  • Blum Pierre-Antoine
  • Charpentier Jean-Pierre
  • Gharbi Hakim
  • Valès Frédéric
  Comptes Rendus. Géoscience, Académie des sciences (Paris), 2004, 336, pp.1337-1344. On décrit des essais de fluage de longue durée sur des éprouvettes de sel gemme soumises à des chargements mécaniques très faibles ($\sigma=0,02$ à $0,1$ MPa). Le chargement était fourni par des charges mortes ; le déplacement était mesuré par des capteurs de résolution $\Delta ɛ=10^{-8}$. On a placé le dispositif d'essai dans une galerie souterraine profonde, où les fluctuations naturelles de température sont de l'ordre du centième de degré Celsius. On a pu ainsi mesurer des vitesses de déformation inférieures à $10^{-12}$/s. Les essais montrent qu'on ne peut extrapoler à ces faibles charges les relations de comportement obtenues sous charge plus élevée. (10.1016/j.crte.2004.09.005)
  DOI : 10.1016/j.crte.2004.09.005
• Lattice friction for crystalline defects: from dislocations to cracks
  
  • Kresse Olga
  • Truskinovsky Lev
  Journal of the Mechanics and Physics of Solids, Elsevier, 2004, 52, pp.2521-2543. We propose a discrete model providing a unified description of lattice induced drag for a class of defects which includes martensitic phase boundaries, dislocations and cracks. Although the model is Hamiltonian, it generates a non-trivial macroscopic friction law which we present as a closed form functional relation between the velocity of the defect and the conjugate configurational force. The possibility to obtain an exact analytic solution of the dynamic problem allows us to expose both the similarities and the differences in the kinetics of various types of defects. In particular, we trace the origin of the symmetry related resonances, specific for dislocations, and show how the flattening of one of the energy wells, indicating transition to fracture, generates a morphological instability of the displacement profile at a critical velocity. (10.1016/j.jmps.2004.04.011)
  DOI : 10.1016/j.jmps.2004.04.011
• Mesure tridimensionnelle de champs cinématiques par imagerie volumique pour l'analyse des matériaux et des structures
  
  • Bornert Michel
  • Chaix Jean-Marc
  • Doumalin Pascal
  • Dupré Jean-Christophe
  • Fournel Thierry
  • Jeulin Dominique
  • Maire Éric
  • Moreaud Maxime
  • Moulinec Hervé
  Instrumentation, Mesure, Métrologie, Lavoisier, 2004, 3-4 (3-4), pp.43-88. Let techniques de corrélation d'images surfaciques sont étendues à l'analyse de don­nées volumiques obtenues par microtomographie X de résolution micrométrique ou, pour les matériaux transparents, par reconstruction sériée avec un éclairage laser plan. Le contraste d'image local est fourni par des marqueurs beaucoup plus petits que let dimensions caracté­ristiques des gradients à analyser, dont on vérifie par simulation qu'ils ne perturbent pas nota­blement ces derniers. Pour la tomograqhie, on ajoute aléatoirement des particules plut denses alors que des diffuseurs optiques sont introduits dans les matériaux transparents. La résolution de mesure, évaluée sur des mouvements rigides, peut descendre à 0,01 voxel, mais se dégrade fortement sur des images bruitées. De nouveaux critères d'appariement, moins sensibles au bruit, sont discutés. Les applications présentées concernent des échantillons plastiques homogènes plats ou entaillés sous traction, ainsi que des composites à matrice métallique et renforts particulaires.
• Evaluation of linearization procedure sustaining nonlinear homogenization theories
  
  • Rekik Amna
  • Bornert Michel
  • Zaoui André
  • Auslender François
  , 2004. A systematic methodology for the evaluation of various existing linearisation procedures sustaining mean field theories for nonlinear composite materials is proposed and applied to the ’modified secant’ and various ’affine’ formulations. It relies on the analysis of a composite for which an exact treatment of both the nonlinear homogenisation problem and the linear homogenisation of the ’linear comparison material’ with identical microstructure is possible; the effects of the sole linearization method can then be evaluated.
• Elements of poro-micromechanics applied to concrete
  
  • Dormieux L.
  • Lemarchand E.
  • Kondo D.
  • Fairbairn E.
  Materials and structures, Springer Verlag, 2004, 37 (1), pp.31-42. (10.1007/BF02481625)
  DOI : 10.1007/BF02481625
• T.G.V. disk brake squeal: a dynamic instability?
  
  • Lorang Xavier
  • Nguyen Quoc Son
  • Foy-Margiocchi Florence
  • Gautier Etienne
  , 2004, pp.959-960.
• Characterization of Local Strain Field in Cortical Bone
  
  • Henry L.
  • Meunier A.
  • Aubry Denis
  • Crépin Jérôme
  • Caldemaison D.
  • Hoc T.
  , 2004. No abstract provided
• Etude expérimentale et modélisation du comportement mécanique des alliages TiAl à l'échelle du grain
  
  • E. Héripré E.
  • Crépin Jérôme
  • Roos A.
  • Chaboche J. L.
  , 2004. No abstract provided
• Identification of crystalline behavior on macroscopic response and local strain field analysis: application to alpha zirconium alloys
  
  • Gélébart Lionel
  • Crépin Jérôme
  • Dexet Marie
  • Sauzay Maxime
  • Roos Arjen
  Journal of ASTM International (JAI), ASTM, 2004, 1. The purpose of this paper is to present an identification method of the crystalline behavior of a material from a mechanical test performed on a polycrystalline sample. Because of the lack of knowledge about its crystalline behavior, this method is applied to a Zirconium alloy. This identification is based on a finite element modeling of the microstructure, and the results are compared to both the macroscopic and the microscopic experimental results. On the microscopic scale, the plastic strains are obtained using a micro-extensometry technique and the crystalline orientation using an EBSD technique. In order to validate the method, an identification is performed with only two free parameters: the evolutions of the macroscopic and microscopic errors appear to be regular and exhibit a well-defined minimum so that the parameters can be clearly identified. (10.1520/JAI12333)
  DOI : 10.1520/JAI12333
• Exact solutions of the interface crack between elastic and rigid bodies under contact with friction
  
  • Bui Huy Duong
  • Oueslati Abdelbacet
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2004, 332, pp.709-716. One considers an interface crack between an elastic half-plane and a rigid half-plane, in the presence of Coulomb's friction. There exists two singular solutions at the semi-infinite crack tip, which correspond physically to the push-in and the pull-out of a rigid fiber in an elastic matrix. The exact solutions show that only the mode II is present and there is no oscillatory behavior of the stress and the displacement near the crack tip, but an oscillatory behavior is observed at the transition point with the stress free zone. There exists four types of singular solutions for finite crack in bounded medium, but only one in an infinite medium. (10.1016/j.crme.2004.04.008)
  DOI : 10.1016/j.crme.2004.04.008
• Prediction of the weld shape in arc welding
  
  • Roger Frédéric
  • Dang Van Ky
  Revue Européenne des Éléments Finis, HERMÈS / LAVOISIER, 2004, 13 (5-7), pp.713-724. A numerical model of the arc welding process is presented. It deals with all arc welding process with and without filler metal (Gas Metal Arc Welding and Gas Tungsten Arc Welding). We consider the three dimensional modelling of the stationary weld pool with a free deformable surface. All coupled equations are solved by the finite volume method. We consider heat transfer ands fluid flow in the weld pool and the geometry of the free surface subjected to arc pressure and drop impact in GMAW. The location of the energy supplied by drops in the weld pool is assumed to be a function of the Weber number. Comparison with macrography shows a really good agreement of the model. (10.3166/reef.13.713-724)
  DOI : 10.3166/reef.13.713-724
• A novel inverse problem in γ-rays emission imaging
  
  • Nguyen Mai K.
  • Truong Tuong T.
  • Bui Huy Duong
  • Delarbre Jean-Luc
  Inverse Problems in Science and Engineering, Taylor & Francis, 2004, 12 (2), pp.225-246. This article presents a recent result on the feasibility of reconstruction of the radioactivity distribution of an object from a sequence of Compton-scattered radiation data in emission imaging. This may be regarded as a novel inverse principle as opposed to the traditional one in which the object is reconstructed only from the non-scattered rays collected at different incident directions. The new inversion procedure is described by an invertible linear integral transform which may be viewed as a generalized Radon transform and has several advantages over the old one. It improves significantly the contrast of the reconstructed image. The required data for reconstruction is easily acquired from an energy and position sensitive gamma camera under the form of scattered distribution images classified by their Compton-scattering angle. The motion of the camera in standard tomographic procedure is here no longer necessary for data taking. (10.1080/10682760310001598661)
  DOI : 10.1080/10682760310001598661
• Contribution to the definition of a partial overlapping plastic strain rates domain for moderate loadings - application to tensile testing on metallic materials
  
  • Haugou Grégory
  • Markiewicz Eric
  • Fabis Jacky
  • Gary Gérard
  International Journal of Crashworthiness, Taylor & Francis, 2004, 9 (2), pp.187-194. Generally, tensile testing on Hopkinson bars requires some particular considerations. Most of the specific devices, designed to hold tensile sheet specimens on the bars, involve the degradation of the pulses in particular case of no-direct tensile loadings. A tensile testing configuration for sheet specimens is proposed on the basis of classical split Hopkinson pressure bars (SHPB). Specimens holding is obtained with an epoxy adhesive and provides good measurements on sheet specimens. A comparison is made for the same two metallic materials results extracted from literature and dynamic tensile tests performed with a high speed hydraulic machine and another split Hopkinson bars (SHPB) facility using hat-specimens. A partial overlapping domain in terms of plastic strain is shown at moderate strain rates from 200 to 400 s−1. (10.1533/ijcr.2004.0278)
  DOI : 10.1533/ijcr.2004.0278
• Incompressibility constraints in finite elements
  
  • Le Tallec Patrick
  , 2004, pp.33-45.
• Stick-slip-separation waves under frictional and unilateral contact
  
  • Oueslati Abdelbacet
  • Son Nguyen Quoc
  Revue Européenne des Éléments Finis, HERMÈS / LAVOISIER, 2004, 13, pp.617-626. The dynamical problem of a brake-like mechanical system composed of an elastic cylindrical tube with Coulomb's friction in contact with a rigid and rotating cylinder is considered. This model problem enables us to give an example of non-trivial periodic solutions in the form of stick-slip or stick-slip-separation waves propagating on the contact surface. It is shown in particular that the stick-slip-separation solutions would occur for small normal pressures or high rotational speeds. The existence and the characteristics of stick-slip and stick-slip-separation waves are discussed numerically.
• On the Ekberg, Kabo and Andersson calculation of the Dang Van high cycle fatigue limit for rolling contact fatigue
  
  • Ciavarella M.
  • Maitournam Habibou
  Fatigue and Fracture of Engineering Materials and Structures, Wiley-Blackwell, 2004, 27, pp.523-526. Recently, various methods have been proposed to assess the risk of rolling contact fatigue failure by Ekberg, Kabo and Andersson, and in particular, the Dang Van multiaxial fatigue criterion has been suggested in a simple approximate formulation. In this note, it is found that the approximation implied can be very significant; the calculation is improved and corrected, and focused on the study of plane problems but for a complete range of possible friction coefficients. It is found that predicted fatigue limit could be much higher than that under standard uniaxial tension/compression for ‘hard materials’ than for ‘ductile materials.’ This is in qualitative agreement, for example, with gears' design standards, but in quantitative terms, particularly for frictionless condition, the predicted limit seems possibly too high, indicating the need for careful comparison with experimental results. Some comments are devoted to the interplay of shakedown and fatigue. (10.1111/j.1460-2695.2004.00772.x)
  DOI : 10.1111/j.1460-2695.2004.00772.x
• An estimate of maximum ground surface motion for non zero surface velocity
  
  • Pecker Alain
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2004, 332, pp.725-730. The increasing need for probability seismic hazard assessment (PSHA) of critical facilities sometimes leads to unrealistic earthquake scenarios with very high induced ground motions. From a physical standpoint these high motions cannot exist because of the limiting resistance capacity of the soil strata through which the seismic waves travel. A simple analytical model is proposed to bound the maximum ground surface acceleration that any soil deposit can transfer. This model is an extension to non zero ground surface velocity of a previously presented model. (10.1016/j.crme.2004.04.005)
  DOI : 10.1016/j.crme.2004.04.005