https://sam.ensam.eu:443 The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material. Wed, 16 Sep 2026 18:16:56 GMT 2026-09-16T18:16:56Z http://hdl.handle.net/10985/10355 Modélisation Elasto-Viscoplastique du Comportement des Aciers PIPARD, Jean-Marc; ABED-MERAIM, Farid; BALAN, Tudor; BERVEILLER, Marcel; BOUAZIZ, Olivier; LEMOINE, Xavier Dans cet article, une modélisation des différentes phases (ferrite, perlite etc.…) d’un acier multiphasé est proposée moyennant une loi phénoménologique à base physique. La description unifiée du comportement viscoplastique peut être décrite à partir de lois de type sinus hyperbolique. Dans cette optique, une loi en sinus hyperbolique est utilisée afin de décrire de façon physiquement acceptable l’ensemble des comportements asymptotiques du comportement viscoplastique. L’écrouissage de chacune des phases est de type combiné (isotrope et cinématique) incluant l’effet de vitesse de déformation propre au comportement visqueux. A partir d’un modèle de comportement monotone unidimensionnel d’inspiration métallurgique, nous développons une formulation tridimensionnelle incrémentale, en déterminant l’expression du potentiel dont découlent les lois de comportement correspondantes. La capacité du modèle ainsi obtenu à décrire le comportement élasto-viscoplastique d’une phase est testée au travers de simulations de tests rhéologiques décrivant différents chemins de déformation à différentes vitesses de déformation. Une discussion basée sur la comparaison de ces simulations avec des résultats expérimentaux sur un acier 100% ferritique est présentée.; In this work, an elastic-viscoplastic behaviour modelling of multi-phase steels at large strain-rates is presented. For each phase (ferrrite, perlite etc…), an advanced physically based viscoplastic constitutive model is adopted. Viscoplastic behaviour can be described by hyperbolic sine function. A new physically based constitutive law suitable to capture all the main features of viscoplasticity is used. In this study, the model has been extended to three dimensional framework in view of numerical implementation in a finite element code. The ability of this modelling framework to describe the behaviour of steels at high strain-rates is explored by means of simulations of rheological tests at various strain-rates and involving different strain paths. The model is applied to a 100% polycrystalline ferritic steel. Numerical results in terms of strain rate sensitivity and Bauschinger effect are discussed and compared with experimental ones. Mon, 01 Jan 2007 00:00:00 GMT http://hdl.handle.net/10985/10355 2007-01-01T00:00:00Z PIPARD, Jean-Marc ABED-MERAIM, Farid BALAN, Tudor BERVEILLER, Marcel BOUAZIZ, Olivier LEMOINE, Xavier Dans cet article, une modélisation des différentes phases (ferrite, perlite etc.…) d’un acier multiphasé est proposée moyennant une loi phénoménologique à base physique. La description unifiée du comportement viscoplastique peut être décrite à partir de lois de type sinus hyperbolique. Dans cette optique, une loi en sinus hyperbolique est utilisée afin de décrire de façon physiquement acceptable l’ensemble des comportements asymptotiques du comportement viscoplastique. L’écrouissage de chacune des phases est de type combiné (isotrope et cinématique) incluant l’effet de vitesse de déformation propre au comportement visqueux. A partir d’un modèle de comportement monotone unidimensionnel d’inspiration métallurgique, nous développons une formulation tridimensionnelle incrémentale, en déterminant l’expression du potentiel dont découlent les lois de comportement correspondantes. La capacité du modèle ainsi obtenu à décrire le comportement élasto-viscoplastique d’une phase est testée au travers de simulations de tests rhéologiques décrivant différents chemins de déformation à différentes vitesses de déformation. Une discussion basée sur la comparaison de ces simulations avec des résultats expérimentaux sur un acier 100% ferritique est présentée. In this work, an elastic-viscoplastic behaviour modelling of multi-phase steels at large strain-rates is presented. For each phase (ferrrite, perlite etc…), an advanced physically based viscoplastic constitutive model is adopted. Viscoplastic behaviour can be described by hyperbolic sine function. A new physically based constitutive law suitable to capture all the main features of viscoplasticity is used. In this study, the model has been extended to three dimensional framework in view of numerical implementation in a finite element code. The ability of this modelling framework to describe the behaviour of steels at high strain-rates is explored by means of simulations of rheological tests at various strain-rates and involving different strain paths. The model is applied to a 100% polycrystalline ferritic steel. Numerical results in terms of strain rate sensitivity and Bauschinger effect are discussed and compared with experimental ones. http://hdl.handle.net/10985/10021 Physically-motivated elasto-visco-plastic model for the large strain-rate behavior of steels PIPARD, Jean-Marc; BALAN, Tudor; ABED-MERAIM, Farid; LEMOINE, Xavier A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for a DD14 mild steel. The model requires significantly fewer material parameters compared to other visco-plasticity models from the literature while exhibiting very good accuracy. Accordingly, the parameter identification is simple and intuitive, requiring a relatively small set of experiments. The strain-rate sensitivity modeling is not restricted to a particular hardening law and thus provides a general framework in which advanced hardening equations can be adopted and compared. The model has been implemented in the commercial finite element code Abaqus/Explicit. First predictions compared to experiments are analyzed and underline the effect of hardening law and strain-rate sensitivity on 3D finite element simulations. The model has been also applied as the basis for a homogenization approach at the phase scale; preliminary investigations showed the benefits of coupling such an approach with scale-transition technique where microstructure-relevant data can explicitly enter the model and may be used for material design simulations. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/10021 2013-01-01T00:00:00Z PIPARD, Jean-Marc BALAN, Tudor ABED-MERAIM, Farid LEMOINE, Xavier A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for a DD14 mild steel. The model requires significantly fewer material parameters compared to other visco-plasticity models from the literature while exhibiting very good accuracy. Accordingly, the parameter identification is simple and intuitive, requiring a relatively small set of experiments. The strain-rate sensitivity modeling is not restricted to a particular hardening law and thus provides a general framework in which advanced hardening equations can be adopted and compared. The model has been implemented in the commercial finite element code Abaqus/Explicit. First predictions compared to experiments are analyzed and underline the effect of hardening law and strain-rate sensitivity on 3D finite element simulations. The model has been also applied as the basis for a homogenization approach at the phase scale; preliminary investigations showed the benefits of coupling such an approach with scale-transition technique where microstructure-relevant data can explicitly enter the model and may be used for material design simulations. http://hdl.handle.net/10985/9906 Elasto-visco-plastic modeling of mild steels for sheet forming applications over a large range of strain rates PIPARD, Jean-Marc; BALAN, Tudor; ABED-MERAIM, Farid; LEMOINE, Xavier A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for three different mild steels. The experiments consist of tensile tests ranging from quasi-static conditions up to strain rates of 103 s-1 as well as quasi-static simple and reverse shear tests at different amounts of pre-strain. Additional two-step sequential mechanical tests (Bauschinger and orthogonal effects) have been performed to further evaluate the ability of the model to describe strain-path changes at moderate/large strains. The model requires significantly fewer material parameters compared to other visco-plasticity models from the literature, while being able to describe some of the main features of the strain-rate sensitivity of mild steels. Accordingly, the parameter identification is simple and intuitive, requiring a relatively small set of experiments. The strain-rate sensitivity modeling is not restricted to a particular hardening law and thus provides a general framework in which advanced hardening equations can be adopted. Tue, 01 Jan 2013 00:00:00 GMT http://hdl.handle.net/10985/9906 2013-01-01T00:00:00Z PIPARD, Jean-Marc BALAN, Tudor ABED-MERAIM, Farid LEMOINE, Xavier A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for three different mild steels. The experiments consist of tensile tests ranging from quasi-static conditions up to strain rates of 103 s-1 as well as quasi-static simple and reverse shear tests at different amounts of pre-strain. Additional two-step sequential mechanical tests (Bauschinger and orthogonal effects) have been performed to further evaluate the ability of the model to describe strain-path changes at moderate/large strains. The model requires significantly fewer material parameters compared to other visco-plasticity models from the literature, while being able to describe some of the main features of the strain-rate sensitivity of mild steels. Accordingly, the parameter identification is simple and intuitive, requiring a relatively small set of experiments. The strain-rate sensitivity modeling is not restricted to a particular hardening law and thus provides a general framework in which advanced hardening equations can be adopted.