Jean-Louis Chaboche

Bio: Jean-Louis Chaboche is an academic researcher from Office National d'Études et de Recherches Aérospatiales. The author has contributed to research in topics: Viscoplasticity & Constitutive equation. The author has an hindex of 41, co-authored 110 publications receiving 17776 citations. Previous affiliations of Jean-Louis Chaboche include Université Paris-Saclay & University of Technology of Troyes.

Mechanics of Solid Materials

Abstract: 1. Elements of the physical mechanisms of deformation and fracture 2. Elements of continuum mechanics and thermodynamics 3. Identification and theological classification of real solids 4. Linear elasticity, thermoelasticity and viscoelasticity 5. Plasticity 6. Viscoplasticity 7. Damage mechanics 8. Crack mechanics.

Constitutive equations for cyclic plasticity and cyclic viscoplasticity

Abstract: The cyclic constitutive equations developed and used at ONERA and LMT-Cachan are presented in detail in terms of a hierarchy of various models. Both the time-independent and the viscoplasticity versions of the equations are discussed, as well as their ability to describe correctly most of the experimentally observed effects under monotonic or cyclic loading, constant or variable temperature, including strain hardening and time recovery effects. The reported experimental data concerns stainless steels and have been published previously. Four other theories are then presented and compared in a systematic way. They include the Ohno-Kachi time-independent plasticity theory, two unified viscoplastic models by Walker and by Krempl and Yao, the new developments of the endochronic theory by Watanabe and Atluri. All these approaches show some similarities with the first one, especially i that concerns the non-linearity of kinematic hardening, which represents the key for describing the cyclic behaviour of metallic materials.

A review of some plasticity and viscoplasticity constitutive theories

Abstract: The purpose of the present review article is twofold: • recall elementary notions as well as the main ingredients and assumptions of developing macroscopic inelastic constitutive equations, mainly for metals and low strain cyclic conditions The explicit models considered have been essentially developed by the author and co-workers, along the past 30 years; • summarize and discuss a certain number of alternative theoretical frameworks, with some comparisons made with the previous ones, including more recent developments that offer potential new capabilities

Time-independent constitutive theories for cyclic plasticity

Abstract: The article is mainly concerned with time-independent plasticity in the range of cyclic loadings. Three different approaches are considered for the description of kinematic behaviour: (i) the use of independent multiyield surfaces, (ii) models with two surfaces only, (iii) the so-called “nonlinear-kinematic hardening rule” defined by a differential equation. The thermodynamic framework from which the third approach is derived and the conditions of varying temperature are considered. Connections between the three kinds of models are pointed out. Also, some specific rules to describe cyclic hardening or cyclic softening of the material are proposed. Finally, the limits of the models considered, and the difficulties associated with their practical use and their implementation in computer codes are discussed in detail.

Mécanique des matériaux solides

Abstract: Keywords: Rheologie ; Milieux continus ; Plasticite ; Fissuration Reference Record created on 2004-09-07, modified on 2016-08-08

Plastic-Damage Model for Cyclic Loading of Concrete Structures

Abstract: A new plastic-damage model for concrete subjected to cyclic loading is developed using the concepts of fracture-energy-based damage and stiffness degradation in continuum damage mechanics. Two damage variables, one for tensile damage and the other for compressive damage, and a yield function with multiple-hardening variables are introduced to account for different damage states. The uniaxial strength functions are factored into two parts, corresponding to the effective stress and the degradation of elastic stiffness. The constitutive relations for elastoplastic responses are decoupled from the degradation damage response, which provides advantages in the numerical implementation. In the present model, the strength function for the effective stress is used to control the evolution of the yield surface, so that calibration with experimental results is convenient. A simple and thermodynamically consistent scalar degradation model is introduced to simulate the effect of damage on elastic stiffness and its recovery during crack opening and closing. The performance of the plastic-damage model is demonstrated with several numerical examples of simulating monotonically and cyclically loaded concrete specimens.

A continuous damage mechanics model for ductile fracture

Abstract: A model of isotropic ductile plastic damage based on a continuum damage variable, on the effective stress concept and on thermodynamics is derived. The damage is linear with equivalent strain and shows a large influence of triaxiality by means of a damage equivalent stress. Identification for several metals is made by means of elasticity modulus change induced by damage. A comparison with the McClintock and Rice-Tracey models and with some experiments is presented for the influence of triaxiality on the strain to rupture.

Nonlocal damage theory

Abstract: In the usual local finite element analysis, strain softening causes spurious mesh sensitivity and incorrect convergence when the element is refined to vanishing size. In a previous continuum formulation, these incorrect features were overcome by the imbricate nonlocal continuum, which, however, introduced some unnecessary computational complications due to the fact that all response was treated as nonlocal. The key idea of the present nonlocal damage theory is to subject to nonlocal treatment only those variables that control strain softening, and to treat the elastic part of the strain as local. The continuum damage mechanics formulation, convenient for separating the nonlocal treatment of damage from the local treatment of elastic behavior, is adopted in the present work. The only required modification is to replace the usual local damage energy release rate with its spatial average over the representative volume of the material whose size is a characteristic of the material. Avoidance of spurious mesh ...

A mathematical representation of the multiaxial Bauschinger effect

Abstract: (2007) A mathematical representation of the multiaxial Bauschinger effect Materials at High Temperatures: Vol 24, No 1, pp 1-26

Overview of constitutive laws, kinematics, homogenization and multiscale methods in crystal plasticity finite-element modeling: Theory, experiments, applications

Abstract: This article reviews continuum-based variational formulations for describing the elastic–plastic deformation of anisotropic heterogeneous crystalline matter. These approaches, commonly referred to as crystal plasticity finite-element models, are important both for basic microstructure-based mechanical predictions as well as for engineering design and performance simulations involving anisotropic media. Besides the discussion of the constitutive laws, kinematics, homogenization schemes and multiscale approaches behind these methods, we also present some examples, including, in particular, comparisons of the predictions with experiments. The applications stem from such diverse fields as orientation stability, microbeam bending, single-crystal and bicrystal deformation, nanoindentation, recrystallization, multiphase steel (TRIP) deformation, and damage prediction for the microscopic and mesoscopic scales and multiscale predictions of rolling textures, cup drawing, Lankfort ( r ) values and stamping simulations for the macroscopic scale.