The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
J.w. Yoon - One of the best experts on this subject based on the ideXlab platform.
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A novel approach for anisotropic hardening modeling. Part II: Anisotropic hardening in proportional and non-proportional loadings, application to initially isotropic Material
International Journal of Plasticity, 2010Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:The modeling of anisotropic hardening, in particular for non-proportional loading paths, is a challenging task for advanced macroscopic models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms can be taken into account in polycrystalline models but the computation times are enormous. The novel approach detailed in Part I (Rousselier et al., 2009) consists in: (i) drastically reducing the number of crystallographic orientations to save the computation cost, (ii) applying a parameter calibration procedure to obtain a good agreement with the experimental database. This methodology is first applied here to the anisotropic hardening in the proportional loadings of the strongly anisotropic aluminum alloy of Part I. Very good modeling is achieved with only eight crystallographic orientations. Different levels of additional hardening in biaxial proportional loading as compared to uniaxial loading can be modeled with the same polycrystalline model. For this, only the parameter calibration has to be performed with different databases. The same methodology has also been applied for the modeling of isotropic behavior. The best compromise between model accuracy and numerical cost is obtained with fourteen orientations. The deviations from isotropy are acceptable in all loading directions. Different levels of hardening in orthogonal loading: simple shear followed by simple tension, are achieved without any modification of the model equations. Only the parameter calibration has to be performed with different hardening levels in the database. FE calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only five times larger than that with the simple von Mises model. The CPU time with texture evolution is further increased by a factor of two. The effects of texture evolution in rolling of the initially isotropic Fcc Material have been investigated. The resulting texture and hardening are qualitatively good.
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A novel approach for anisotropic hardening modeling. Part I: Theory and its application to finite element analysis of deep drawing
International Journal of Plasticity, 2009Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:Advanced macroscopic models give a good description of initial plastic behavior of most metallic Materials like initial anisotropy. However, the modeling of anisotropic hardening, in particular for non-proportional loading paths, still is a difficult task for these models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms are taken into account in polycrystalline models. The novel approach consists in: (i) drastically reducing the number of crystallographic orientations, (ii) applying a specific parameter calibration procedure to obtain a good agreement with all stress–strain and transverse strains curves of an extended experimental database including pseudo-experimental tests. In the present study, the methodology has been applied to a strongly anisotropic aluminum alloy (Part I) and to an initially isotropic Fcc Material (Part II, submitted to Int. J. Plasticity). Very good modeling is achieved with 8 and 14 crystallographic orientations, respectively, in particular for the Lankford ratios along different loading directions. The additional hardening for non-proportional loadings, such as simple shear followed by tension, can be modeled. The effects of texture evolution are also qualitatively investigated. It must be emphasized that the objective of the methodology is not to obtain results at the microscopic scale or Material science level. The polycrystalline models are used in the same way as macroscopic models are, provided the computation times are similar. In order to validate the methodology and to evaluate its performance, finite element calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only twice larger than the one with an advanced anisotropic macroscopic model. The calculated cup heights with six ears are in good agreement with the experimental measurements.
Gilles Rousselier - One of the best experts on this subject based on the ideXlab platform.
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A novel approach for anisotropic hardening modeling. Part II: Anisotropic hardening in proportional and non-proportional loadings, application to initially isotropic Material
International Journal of Plasticity, 2010Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:The modeling of anisotropic hardening, in particular for non-proportional loading paths, is a challenging task for advanced macroscopic models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms can be taken into account in polycrystalline models but the computation times are enormous. The novel approach detailed in Part I (Rousselier et al., 2009) consists in: (i) drastically reducing the number of crystallographic orientations to save the computation cost, (ii) applying a parameter calibration procedure to obtain a good agreement with the experimental database. This methodology is first applied here to the anisotropic hardening in the proportional loadings of the strongly anisotropic aluminum alloy of Part I. Very good modeling is achieved with only eight crystallographic orientations. Different levels of additional hardening in biaxial proportional loading as compared to uniaxial loading can be modeled with the same polycrystalline model. For this, only the parameter calibration has to be performed with different databases. The same methodology has also been applied for the modeling of isotropic behavior. The best compromise between model accuracy and numerical cost is obtained with fourteen orientations. The deviations from isotropy are acceptable in all loading directions. Different levels of hardening in orthogonal loading: simple shear followed by simple tension, are achieved without any modification of the model equations. Only the parameter calibration has to be performed with different hardening levels in the database. FE calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only five times larger than that with the simple von Mises model. The CPU time with texture evolution is further increased by a factor of two. The effects of texture evolution in rolling of the initially isotropic Fcc Material have been investigated. The resulting texture and hardening are qualitatively good.
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A novel approach for anisotropic hardening modeling. Part I: Theory and its application to finite element analysis of deep drawing
International Journal of Plasticity, 2009Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:Advanced macroscopic models give a good description of initial plastic behavior of most metallic Materials like initial anisotropy. However, the modeling of anisotropic hardening, in particular for non-proportional loading paths, still is a difficult task for these models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms are taken into account in polycrystalline models. The novel approach consists in: (i) drastically reducing the number of crystallographic orientations, (ii) applying a specific parameter calibration procedure to obtain a good agreement with all stress–strain and transverse strains curves of an extended experimental database including pseudo-experimental tests. In the present study, the methodology has been applied to a strongly anisotropic aluminum alloy (Part I) and to an initially isotropic Fcc Material (Part II, submitted to Int. J. Plasticity). Very good modeling is achieved with 8 and 14 crystallographic orientations, respectively, in particular for the Lankford ratios along different loading directions. The additional hardening for non-proportional loadings, such as simple shear followed by tension, can be modeled. The effects of texture evolution are also qualitatively investigated. It must be emphasized that the objective of the methodology is not to obtain results at the microscopic scale or Material science level. The polycrystalline models are used in the same way as macroscopic models are, provided the computation times are similar. In order to validate the methodology and to evaluate its performance, finite element calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only twice larger than the one with an advanced anisotropic macroscopic model. The calculated cup heights with six ears are in good agreement with the experimental measurements.
Frédéric Barlat - One of the best experts on this subject based on the ideXlab platform.
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A novel approach for anisotropic hardening modeling. Part II: Anisotropic hardening in proportional and non-proportional loadings, application to initially isotropic Material
International Journal of Plasticity, 2010Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:The modeling of anisotropic hardening, in particular for non-proportional loading paths, is a challenging task for advanced macroscopic models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms can be taken into account in polycrystalline models but the computation times are enormous. The novel approach detailed in Part I (Rousselier et al., 2009) consists in: (i) drastically reducing the number of crystallographic orientations to save the computation cost, (ii) applying a parameter calibration procedure to obtain a good agreement with the experimental database. This methodology is first applied here to the anisotropic hardening in the proportional loadings of the strongly anisotropic aluminum alloy of Part I. Very good modeling is achieved with only eight crystallographic orientations. Different levels of additional hardening in biaxial proportional loading as compared to uniaxial loading can be modeled with the same polycrystalline model. For this, only the parameter calibration has to be performed with different databases. The same methodology has also been applied for the modeling of isotropic behavior. The best compromise between model accuracy and numerical cost is obtained with fourteen orientations. The deviations from isotropy are acceptable in all loading directions. Different levels of hardening in orthogonal loading: simple shear followed by simple tension, are achieved without any modification of the model equations. Only the parameter calibration has to be performed with different hardening levels in the database. FE calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only five times larger than that with the simple von Mises model. The CPU time with texture evolution is further increased by a factor of two. The effects of texture evolution in rolling of the initially isotropic Fcc Material have been investigated. The resulting texture and hardening are qualitatively good.
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A novel approach for anisotropic hardening modeling. Part I: Theory and its application to finite element analysis of deep drawing
International Journal of Plasticity, 2009Co-Authors: Gilles Rousselier, Frédéric Barlat, J.w. YoonAbstract:Advanced macroscopic models give a good description of initial plastic behavior of most metallic Materials like initial anisotropy. However, the modeling of anisotropic hardening, in particular for non-proportional loading paths, still is a difficult task for these models. The complex distortion of the yield locus is related to the activation and cross-hardening of different slip systems, depending on crystallographic orientations. These physical mechanisms are taken into account in polycrystalline models. The novel approach consists in: (i) drastically reducing the number of crystallographic orientations, (ii) applying a specific parameter calibration procedure to obtain a good agreement with all stress–strain and transverse strains curves of an extended experimental database including pseudo-experimental tests. In the present study, the methodology has been applied to a strongly anisotropic aluminum alloy (Part I) and to an initially isotropic Fcc Material (Part II, submitted to Int. J. Plasticity). Very good modeling is achieved with 8 and 14 crystallographic orientations, respectively, in particular for the Lankford ratios along different loading directions. The additional hardening for non-proportional loadings, such as simple shear followed by tension, can be modeled. The effects of texture evolution are also qualitatively investigated. It must be emphasized that the objective of the methodology is not to obtain results at the microscopic scale or Material science level. The polycrystalline models are used in the same way as macroscopic models are, provided the computation times are similar. In order to validate the methodology and to evaluate its performance, finite element calculations of a deep drawing test have been performed. The CPU time of the polycrystalline model is only twice larger than the one with an advanced anisotropic macroscopic model. The calculated cup heights with six ears are in good agreement with the experimental measurements.
Bert Verlinden - One of the best experts on this subject based on the ideXlab platform.
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prediction of the tension compression asymmetry of ecap processed Fcc Material using an integrated model based on dislocation and back stress
Materials Science Forum, 2010Co-Authors: En Ze Chen, Laurent Duchene, Anne Habraken, Bert VerlindenAbstract:In our recent work, a new integrated model was proposed to describe the back-stress evolution based on the dislocation substructure and texture. By relating the back-stress to the dislocation density in cell walls and in the cell interior, this model is able to capture the back-stress evolution of ECAP processed pure aluminium. In this paper, the model is used for another Fcc Material, namely copper. The aim is to check whether this model is able to predict the tension/compression asymmetry (due to the back-stress) of copper. The results show that this is indeed the case and it is also found that the strain rate ratio proposed in our previous work [1] is a function of the dislocation density ratio.
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Prediction of the Tension/Compression Asymmetry of ECAP Processed Fcc Material Using an Integrated Model Based on Dislocation and Back-Stress
Materials Science Forum, 2010Co-Authors: En Ze Chen, Laurent Duchene, Anne Habraken, Bert VerlindenAbstract:In our recent work, a new integrated model was proposed to describe the back-stress evolution based on the dislocation substructure and texture. By relating the back-stress to the dislocation density in cell walls and in the cell interior, this model is able to capture the back-stress evolution of ECAP processed pure aluminium. In this paper, the model is used for another Fcc Material, namely copper. The aim is to check whether this model is able to predict the tension/compression asymmetry (due to the back-stress) of copper. The results show that this is indeed the case and it is also found that the strain rate ratio proposed in our previous work [1] is a function of the dislocation density ratio.
En Ze Chen - One of the best experts on this subject based on the ideXlab platform.
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prediction of the tension compression asymmetry of ecap processed Fcc Material using an integrated model based on dislocation and back stress
Materials Science Forum, 2010Co-Authors: En Ze Chen, Laurent Duchene, Anne Habraken, Bert VerlindenAbstract:In our recent work, a new integrated model was proposed to describe the back-stress evolution based on the dislocation substructure and texture. By relating the back-stress to the dislocation density in cell walls and in the cell interior, this model is able to capture the back-stress evolution of ECAP processed pure aluminium. In this paper, the model is used for another Fcc Material, namely copper. The aim is to check whether this model is able to predict the tension/compression asymmetry (due to the back-stress) of copper. The results show that this is indeed the case and it is also found that the strain rate ratio proposed in our previous work [1] is a function of the dislocation density ratio.
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Prediction of the Tension/Compression Asymmetry of ECAP Processed Fcc Material Using an Integrated Model Based on Dislocation and Back-Stress
Materials Science Forum, 2010Co-Authors: En Ze Chen, Laurent Duchene, Anne Habraken, Bert VerlindenAbstract:In our recent work, a new integrated model was proposed to describe the back-stress evolution based on the dislocation substructure and texture. By relating the back-stress to the dislocation density in cell walls and in the cell interior, this model is able to capture the back-stress evolution of ECAP processed pure aluminium. In this paper, the model is used for another Fcc Material, namely copper. The aim is to check whether this model is able to predict the tension/compression asymmetry (due to the back-stress) of copper. The results show that this is indeed the case and it is also found that the strain rate ratio proposed in our previous work [1] is a function of the dislocation density ratio.
