Afin de decrire le comportement de structures en beton, un modele d'endommagement "imple... more Afin de decrire le comportement de structures en beton, un modele d'endommagement "implemente" dans un code elements finis est utilise. Apres une courte description des concepts introduits, les applications au beton arme et precontraint sont presentees. La comparaison avec les resultats experimentaux montre que cette approche donne une prevision exacte du comportement ainsi qu'une bonne prevision de la rupture de ce genre de structures. (A). (Voir fiche generale DIRR 125234).
This paper deals with the behavior of reinforced concrete bearing walls subjected to seismic load... more This paper deals with the behavior of reinforced concrete bearing walls subjected to seismic loading. The presentation focuses on the numerical tools dedicated to nonlinear transient simplified analysis allowing parametrical studies. In a first step, the multifibers beam approach is presented as well as the local nonlinear constitutive equations. Comparisons between experimental results and numerical computation for 2-D and 3-D case-study are presented.
Fracture and damage modelling centrifuge studies hydraulic and thermal coupling time-dependent ef... more Fracture and damage modelling centrifuge studies hydraulic and thermal coupling time-dependent effects and alkali-reactons applications Case studies.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2016
Based on previous work, the µ damage model has been designed to figure out the various damage eff... more Based on previous work, the µ damage model has been designed to figure out the various damage effects in concrete correlated with monotonic and cyclic loading, including unilateral effects. Assumptions are formulated to simplify constitutive relationships while still allowing for a correct description of the main nonlinear effects. In this context, the paper presents an enhanced simplified finite-element description including a damage description, based on the use of multifibre beam elements and including strain rate effects. Applications show that such a strategy leads to an efficient tool to simulate dynamic loading at low, medium and high velocities. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
This paper presents a review of the different models for concrete based on continuum damage theor... more This paper presents a review of the different models for concrete based on continuum damage theory, formulated at the Laboratoire de Mécanique et Technologie (Cachan, France). Derived in the framework of the thermodynamics of irreversible processes, each formulation is ...
Dans le cadre du programme national "Conception et Evaluation des Ouvrages Speciaux" (C... more Dans le cadre du programme national "Conception et Evaluation des Ouvrages Speciaux" (CEOS.fr), une etude d'un tirant en beton arme a ete effectuee en utilisant un modele d’endommagement non local (Mazars) pour le beton et un modele elasto-plastique pour les armatures. Une methode de postraitement des zones endommagees permet de caracteriser la fissuration (ouvertures). Une presentation critique des resultats, visant a l’amelioration des strategies de modelisation, sera proposee.
3 SUMMARY Within the framework of the ICONS-TMR research project two five-story buildings, the so... more 3 SUMMARY Within the framework of the ICONS-TMR research project two five-story buildings, the so-called CAMUS III and CAMUS IV specimens, have been tested under dynamic loading in CEA Saclay. Predictive numerical calculations have been made for the two projects using a multi-layered finite element code (EFICOS) and the DYNAFLOW code. The results are compared with those of the previous French research program CAMUS I, a mock-up with the same geometry. Special attention has been paid on the influence of different reinforcement ratios (CAMUS III - CAMUS I) and boundary conditions (CAMUS IV - CAMUS I).
This paper presents a 3D non linear interface element able to compute Soil Structure Interaction ... more This paper presents a 3D non linear interface element able to compute Soil Structure Interaction (SSI). Several approaches exist to take this phenomenon into account: the following work is based on the “macro element” concept and is inspired on the work of (Crémer, 2001). The particularity of the macro element lies in the fact that the movement of the foundation is entirely described by a system of generalised variables (forces and displacements) defined in the foundation centre. The non linear behaviour of the soil is reproduced using the classical theory of plasticity. The failure surface is defined using an adequate overturning mechanism according to the work of (Pecker, 1997). The element is able to simulate the 3D behaviour of a circular rigid shallow foundation under cyclic and dynamic loading considering rocking. It is implemented into FedeasLab, a finite element Matlab toolbox. Comparisons with experimental results under monotonic static (Gottardi et al., 1999), cyclic (TRIS...
Afin de decrire le comportement de structures en beton, un modele d'endommagement "imple... more Afin de decrire le comportement de structures en beton, un modele d'endommagement "implemente" dans un code elements finis est utilise. Apres une courte description des concepts introduits, les applications au beton arme et precontraint sont presentees. La comparaison avec les resultats experimentaux montre que cette approche donne une prevision exacte du comportement ainsi qu'une bonne prevision de la rupture de ce genre de structures. (A). (Voir fiche generale DIRR 125234).
This paper deals with the behavior of reinforced concrete bearing walls subjected to seismic load... more This paper deals with the behavior of reinforced concrete bearing walls subjected to seismic loading. The presentation focuses on the numerical tools dedicated to nonlinear transient simplified analysis allowing parametrical studies. In a first step, the multifibers beam approach is presented as well as the local nonlinear constitutive equations. Comparisons between experimental results and numerical computation for 2-D and 3-D case-study are presented.
Fracture and damage modelling centrifuge studies hydraulic and thermal coupling time-dependent ef... more Fracture and damage modelling centrifuge studies hydraulic and thermal coupling time-dependent effects and alkali-reactons applications Case studies.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2016
Based on previous work, the µ damage model has been designed to figure out the various damage eff... more Based on previous work, the µ damage model has been designed to figure out the various damage effects in concrete correlated with monotonic and cyclic loading, including unilateral effects. Assumptions are formulated to simplify constitutive relationships while still allowing for a correct description of the main nonlinear effects. In this context, the paper presents an enhanced simplified finite-element description including a damage description, based on the use of multifibre beam elements and including strain rate effects. Applications show that such a strategy leads to an efficient tool to simulate dynamic loading at low, medium and high velocities. This article is part of the themed issue ‘Experimental testing and modelling of brittle materials at high strain rates’.
This paper presents a review of the different models for concrete based on continuum damage theor... more This paper presents a review of the different models for concrete based on continuum damage theory, formulated at the Laboratoire de Mécanique et Technologie (Cachan, France). Derived in the framework of the thermodynamics of irreversible processes, each formulation is ...
Dans le cadre du programme national "Conception et Evaluation des Ouvrages Speciaux" (C... more Dans le cadre du programme national "Conception et Evaluation des Ouvrages Speciaux" (CEOS.fr), une etude d'un tirant en beton arme a ete effectuee en utilisant un modele d’endommagement non local (Mazars) pour le beton et un modele elasto-plastique pour les armatures. Une methode de postraitement des zones endommagees permet de caracteriser la fissuration (ouvertures). Une presentation critique des resultats, visant a l’amelioration des strategies de modelisation, sera proposee.
3 SUMMARY Within the framework of the ICONS-TMR research project two five-story buildings, the so... more 3 SUMMARY Within the framework of the ICONS-TMR research project two five-story buildings, the so-called CAMUS III and CAMUS IV specimens, have been tested under dynamic loading in CEA Saclay. Predictive numerical calculations have been made for the two projects using a multi-layered finite element code (EFICOS) and the DYNAFLOW code. The results are compared with those of the previous French research program CAMUS I, a mock-up with the same geometry. Special attention has been paid on the influence of different reinforcement ratios (CAMUS III - CAMUS I) and boundary conditions (CAMUS IV - CAMUS I).
This paper presents a 3D non linear interface element able to compute Soil Structure Interaction ... more This paper presents a 3D non linear interface element able to compute Soil Structure Interaction (SSI). Several approaches exist to take this phenomenon into account: the following work is based on the “macro element” concept and is inspired on the work of (Crémer, 2001). The particularity of the macro element lies in the fact that the movement of the foundation is entirely described by a system of generalised variables (forces and displacements) defined in the foundation centre. The non linear behaviour of the soil is reproduced using the classical theory of plasticity. The failure surface is defined using an adequate overturning mechanism according to the work of (Pecker, 1997). The element is able to simulate the 3D behaviour of a circular rigid shallow foundation under cyclic and dynamic loading considering rocking. It is implemented into FedeasLab, a finite element Matlab toolbox. Comparisons with experimental results under monotonic static (Gottardi et al., 1999), cyclic (TRIS...
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Papers by Jacky Mazars