Publications

2005

• A methodology for seismic vulnerability of masonry arch bridge walls
  
  • Rota M.
  • Pecker Alain
  • Bolognini D.
  • Pinho R.
  Journal of Earthquake Engineering, Taylor & Francis, 2005, 9, special issue 2, pp.331-353. Notwithstanding its potential high level, the seismic vulnerability of masonry arch bridges has yet to completely perceived, possibly due to the relatively scarce damage evidence collected after recent eathquakes. The dearth of research studies on this topic is thus one of the main motivations behind the current endeavour, which aims at a better understanding of the dynamic interaction between the arch walls and the filling material of typical masonry arch bridges, and the consequent susceptibility of the latter to out-of-plane collapse mechanisms. Within this framework, a numerical model for the evaluation of the seismic out-of-plane capacity of bridge walls, including the effects of the infill material, is proposed. This methodology can be subdivided into three main components; computation of static earth pressure, eveluation of dynamic soil thrust, assesment of out-of-plane capacity of masonry wall. In addition, a congruent and relatively simple procedure for the estimation of the seismic demand on the arch wall is described. Finally, a parametric study is carried out with a view to appraise the seismic vulnerability associated to typical masonry arch bridge typologies.
• The non-local generalized standard approach: a consistent gradient theory
  
  • Nguyen Quoc Son
  • Andrieux Stephane
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2005, 333, pp.139-145. In this paper, the generalized standard approach is proposed as a consistent gradient theory to include the gradients of the temperature and of the internal parameter in the set of state variables. This theory is derived from a global point of vue developping the basic ideas of continuum thermodynamics. It leads to the appropriate expressions of the entropy and of the internal energy in terms of the free energy in the case of temperature gradient. The local governing equations of the proposed thermodynamical approach are derived. The formalism of the dissipation potential can be applied in the same spirit as in the classical description from the dissipation analysis. (10.1016/j.crme.2004.09.010)
  DOI : 10.1016/j.crme.2004.09.010
• Inverse acoustic scattering by small-obstacle expansion of cost function
  
  • Guzina B. B.
  • Bonnet Marc
  , 2005. No abstract provided
• IABEM 2004
  
  • Crouch S. L.
  • Bonnet Marc
  , 2005.
• The Reciprocity Gap Functional for Identifying Defects and Cracks
  
  • Bui Huy Duong
  • Constantinescu Andrei
  • Maigre Hubert
  , 2005, 469, pp.17-54. The recovery of defects and cracks in solids using overdetermined boundary data, both the Dirichlet and the Neumann types, is considered in this paper. A review of the method for solving these inverse problems is given, focusing particularly on linearized inverse problems. It is shown how the reciprocity gap functional can solve nonlinear inverse problems involving identification of cracks and distributed defects in bounded solids. Exact solutions for planar cracks in 3D solids are given for static elasticity, heat diffusion and transient acoustics. (10.1007/3-211-38134-1_2)
  DOI : 10.1007/3-211-38134-1_2
• Prise en compte des contraintes résiduelles de traitement thermique dans la prédiction de la tenue en service des culasses en aluminium
  
  • Comte Frédéric
  • Nguyen-Tajan Thi Mac-Lan
  • Morin Nicolas
  • Maitournam Habibou
  • Moumni Ziad
  Mechanics & Industry, EDP Sciences, 2005, 6, pp.343-348. Cet article porte sur la modélisation des culasses aluminium de moteurs diesel HDI en vue de prédire leur tenue en fatigue polycyclique. Celles-ci, avant d'être frettées, serrées sur le bloc moteur et utilisées en service, subissent un traitement thermique (trempe et revenu) afin d'améliorer leurs propriétés mécaniques. Lors de ce procédé d'importantes contraintes résiduelles sont générées. Leur modélisation est nécessaire pour obtenir des résultats numériques prédictifs. Une première difficulté vient de la modélisation des échanges thermiques. Pour cela, le choix d'une fonction analytique simple pour le coefficient d'échange H = f(Tparoi), suivi de l'optimisation des différents paramètres, a permis de modéliser les courbes de refroidissement. Une fois l'histoire thermique de la culasse modélisée, un calcul mécanique élastoplastique permet de déterminer les contraintes résiduelles. Celles-ci, fortement de traction dans la zone à risque, sont défavorables à la tenue à la fatigue polycyclique de la pièce dans le cas de la trempe à l'eau. La prise en compte de l'état résiduel de fin de traitement thermique dans la filière de dimensionnement à la fatigue polycyclique permet alors de caractériser les zones à risque expérimentalement observées. (10.1051/meca:2005039)
  DOI : 10.1051/meca:2005039
• A kinematic interaction model for a large-diameter shaft foundation. An application to seismic demand assessment of a bridge subject to coupled swaying-rocking excitation.
  
  • Beltrami Carlo
  • Lai Carlo G.
  • Pecker Alain
  Journal of Earthquake Engineering, Taylor & Francis, 2005, 9, special issue 2, pp.355-393. The aim of this paper is to illustrate an analytical model for the assessment of kinematic interaction of large-diameter shaft foundations. The model is derived using recently obtained solutions of soil structure interaction problems of rigid walls and fixed base cylinders subjected to a dynamic excitation. The proposed model constitutes an extension to a deformable base of the elastodynamic solution of a rigid fixed-base cylinder imbedded in a homogeneous or inhomogeneous soil stratum with different lateral boundary conditions. The analytical model has been validated by means of a finite elements code and it has been implemented in a consistent seismic soil-structure-interaction analysis procedure. An application of the model to a long, multispan continuous prestressed concrete viaduct with tall piers has been carried out focusing on the importance of kinematic interaction. The main result is that the foundation input motion is characterised not only by a translational horizontal component which is usually of a reduced amplitude if compared with the free-field ground motion, but also by a rotation component that is responsible for a large seismic demand in the superstructure. The proposed model represents an effective tool to be used in the engineering practice to assess both the seismic actions induced by the ground shaking on the foundation system and the effective input motion of a superstructure founded on massive and large diameter shafts
• An exact inversion formula for determining a planar fault from boundary measurements
  
  • Bui Hui Duong
  • Constantinescu Andrei
  • Maigre H.
  Journal of Inverse and Ill-posed Problems, De Gruyter, 2005, 13 (6), pp.553-565. This paper considers the inverse problem of determining a time-dependent slip fault which releases shear stress elastically. The input data for the inverse problem are the accelerations measured on the free external surface. A new formula for determining explicitly the geometry of the planar fault is proposed. Potential applications to real earthquakes are discussed. (10.1515/156939405775199514)
  DOI : 10.1515/156939405775199514
• Softening trigerred by eclogitization, the first step toward exhumation during continental subduction
  
  • Jolivet Laurent
  • Raimbourg Hugues
  • Labrousse Loïc
  • Avigad Dov
  • Leroy Yves
  • Austrheim Håkon
  • Andersen Torgeir B.
  Earth and Planetary Science Letters, Elsevier, 2005, 237, pp.532-547. Direct observation of peak pressure deformation in exhumed subduction channels is difficult because little evidence of this deformation survives later syn-exhumation deformation. Most ultrahigh-pressure parageneses are found in continental derived metamorphic rocks making continental subduction the best context to observe peak pressure deformation. Whereas many studies have enlightened the main driving parameters of exhumation such as buoyancy forces, low viscosity in the subduction channel, overburden removal by erosion and normal faulting, a basic question is seldom considered: why is a tectonic unit disconnected from the descending lithosphere and why does it start its way towards the surface? This event, seminal to exhumation processes, must involve some deformation and decoupling of the exhumed slice from the descending slab at peak pressure conditions or close to it. Our field observations in the Bergen arc show that Caledonian eclogitization and later amphibolitization of a granulitic terrane was achieved with a consistent component of simple shear compatible with the sense of the Caledonian subduction. Thus, the sequence of deformation preserved in the Bergen Arc documents the decoupling of subducted crustal material from the descending slab at the onset of exhumation. This observation suggests that deformation in the subduction channel is largely controlled by kinematic boundary conditions, i.e. underthrusting of the subducting slab. In this context of simple shear, metamorphic reactions assisted by fracturating, fluid infiltration and ductile deformation lower the resistance of rocks and allow the localisation of shear zones and the decoupling of buoyant tectonic units from the subducting slab. These tectonic units can then be incorporated into the channel circulation and start their upward travel. (10.1016/j.epsl.2005.06.047)
  DOI : 10.1016/j.epsl.2005.06.047
• A constitutive model for the fatigue life prediction of rubber
  
  • Raoult Ida
  • Stolz Claude
  • Bourgeois Myriam
  , 2005.
• Modèles de comportement stabilisé anisotrope pour les élastomères
  
  • Raoult Ida
  • Stolz Claude
  • Bourgeois Myriam
  • Nguyen Thi Mac Lan
  • Thomas Jean Jacques
  , 2005.
• Sensitivity analysis for parameter identification in quasi-static poroelasticity
  
  • Lecampion Brice
  • Constantinescu Andrei
  International Journal for Numerical and Analytical Methods in Geomechanics, Wiley, 2005, 29 (2), pp.163-185. This paper is devoted to the formulation of the direct differentiation method and adjoint state method in quasi‐static linear poroelasticity. We derive the strong and weak formulation of both methods and discuss their solutions using the finite element method. The techniques are illustrated and tested on two numerical examples for the case of isotropic and homogeneous material. The presented formulations can be extended to more complex behaviour in poromechanics. (10.1002/nag.409)
  DOI : 10.1002/nag.409
• Dix ans d'acoustique musicale
  
  • Boutillon Xavier
  • Gilbert Joel
  • Vergez Christophe
  Acoustique et Techniques : trimestriel d'information des professionnels de l'acoustique, Neuilly-sur-Seine : Centre d'information et de documentation sur le bruit, 2005, 42-43, pp.1.
• Extracting constitutive parameters from full-field measurements: a review of identification methods
  
  • Bonnet Marc
  • Grediac Michel
  • Hild François
  • Pagano Stéphane
  • Avril Stéphane
  • Pierron Fabrice
  , 2005.
• Homogenization estimates for texture evolution in halite
  
  • Liu Yi
  • Gilormini Pierre
  • Ponte Castañeda Pedro
  Tectonophysics, Elsevier, 2005, 406, pp.179-195. In this work, the recently developed “second-order” self-consistent method [Liu, Y., Ponte Castaneda, P., 2004a. Second-order estimates for the effective behavior and field fluctuations in viscoplastic polycrystals. J. Mech. Phys. Solids 52 467–495] is used to simulate texture evolution in halite polycrystals. This method makes use of a suitably optimized linear comparison polycrystal and has the distinguishing property of being exact to second order in the heterogeneity contrast. The second-order model takes into consideration the effects of hardening and of the evolution of both crystallographic and morphological texture to yield reliable predictions for the macroscopic behavior of the polycrystal. Comparisons of these predictions with full-field numerical simulations [Lebensohn, R.A., Dawson, P.R., Kern, H.M., Wenk, H.R., 2003. Heterogeneous deformation and texture development in halite polycrystals: comparison of different modeling approaches and experimental data. Tectonophysics 370 287–311], as well as with predictions resulting from the earlier “variational” and “tangent” self-consistent models, included here for comparison purposes, provide insight into how the underlying assumptions of the various models affect slip in the grains, and therefore the texture predictions in highly anisotropic and nonlinear polycrystalline materials. The “second-order” self-consistent method, while giving a softer stress-strain response than the corresponding full-field results, predicts a pattern of texture evolution that is not captured by the other homogenization models and that agrees reasonably well with the full-field predictions and with the experimental measures. (10.1016/j.tecto.2005.06.007)
  DOI : 10.1016/j.tecto.2005.06.007
• Fast Multipole Method Applied to 3D BEM for Frequency-Domain Elastodynamics
  
  • Sanz J. A.
  • Bonnet Marc
  , 2005. No abstract provided
• FMM-accelerated computation of topological derivative for 3D acoustic inverse scattering
  
  • Nemitz N.
  • Bonnet Marc
  , 2005. No abstract provided
• Estudo numérico e experimental do comportamento dinâmico da cortiça.
  
  • Gameiro C.P.
  • Cirne J.
  • Gary Gérard
  , 2005, pp.80-82.
• Maximum ground surface motion in probalistic seismic hazard analyses
  
  • Pecker Alain
  Journal of Earthquake Engineering, Taylor & Francis, 2005, 9, special issue 1, pp.187-211. The increasing use of probalistic seismic hazard assessment for critical facilities leads to the consideration of earthquake scenarios with a probality of occurrence as low as 10^-7 per year. For such low probabilities the computed ground accelerations, based on extrapolations of statistical ground motion prediction relationships, may reach values as high as severals g's, which poses tremendous difficulties for earthquake-resistant design.
• Modelling of the scatter in short fatigue cracks growth kinetics in relation with the polycrystalline microstructure
  
  • Bertolino Graciela
  • Doquet V.
  • Sauzay M.
  International Journal of Fatigue, Elsevier, 2005, 27 (5), pp.471-480. Finite element computations of the stresses ahead of a tortuous microcrack in a polycrystal (including crack flanks friction) are coupled with simulations of crystallographic crack growth based on discrete dislocations dynamics. An incubation period for crack growth beyond grain boundaries is introduced. The model reproduces the shape of experimental crack growth curves obtained on 316LN stainless steel and the decrease in arrest periods at grain boundaries as the crack grows. It predicts a large scatter in growth rates related to the variety of local textures. It also describes the fact that overloads allowing arrested cracks to cross the grain boundaries can make small cycles damaging. (10.1016/j.ijfatigue.2004.11.001)
  DOI : 10.1016/j.ijfatigue.2004.11.001
• Identification de modèles probabilistes non paramétriques
  
  • Arnst Maarten
  • Clouteau Didier
  • Bonnet Marc
  , 2005, pp.529-534. (10.1016/j.cma.2007.08.011)
  DOI : 10.1016/j.cma.2007.08.011