Showing results 181 to 200 of 299
  A coupled thermo-viscoplastic formulation at finite strains for the numerical simulation of superplastic forming; Ponthot, Jean-Philippe  in Journal of Materials Processing Technology (2003), 139 This paper deals with a thermo-elasto-viscoplastic formulation for the simulation of metal forming involving large deformations. The authors present the governing equations of the model and some ... [more ▼] This paper deals with a thermo-elasto-viscoplastic formulation for the simulation of metal forming involving large deformations. The authors present the governing equations of the model and some applications to superplastic forming. The numerical examples illustrate the potentiality of the finite-element code METAFOR based on this formulation. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲] Detailed reference viewed: 4 (0 ULg)Parameter identification and shape/process optimization in metal forming simulation; Ponthot, Jean-Philippe in Journal of Materials Processing Technology (2003), 139(1-3), 521-526 Nowadays, computer simulations of metal forming processes using the finite element method (FEM) have reached some level of maturity. The purpose of inverse problems is to determine the simulation input ... [more ▼] Nowadays, computer simulations of metal forming processes using the finite element method (FEM) have reached some level of maturity. The purpose of inverse problems is to determine the simulation input data for one or more of these forming processes, leading to a desired result. The first example is called parameter identification. This consists in evaluating the material parameters for material behavior laws that would lead to the most accurate model, minimizing the difference between experimental results and the corresponding FEM simulation. The second example is initial geometry and tool shape design, consisting in determining the initial shape of the specimen and/or the shape of the forming tools, in order to provide the desired final geometry after the forming process. Both inverse problem examples can be formulated as optimization problems. In this paper, the authors propose to solve these optimization problems with different non-linear optimization methods and to compare their efficiency. (C) 2003 Elsevier Science B.V. All rights reserved. [less ▲] Detailed reference viewed: 19 (2 ULg) Identification of elastoplastic model in large deformation problemsJeunechamps, Pierre-Paul ; Walmag, Jérôme ; Delhez, Eric et alin Cinquini, Carlo (Ed.) Proceedings of the 5th World Congress of Structural and Multidisciplinary Optimization WCSMO5 (2003, May) This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the ... [more ▼] This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the classic Levenberg-Marquardt algorithm. The second one is a trust-region algorithm based on a quadratic model. The two algorithms are compared on two cases, one of them being an actual experiment. [less ▲] Detailed reference viewed: 56 (10 ULg)Optimization of sheet metal forming processes using inverse problems methodology; Ponthot, Jean-Philippe ; Stainier, Laurent in Proceedings of COMPLAS 2003, VII International Conference on Computational Plasticity. Fundamentals and Applications (2003, April) Detailed reference viewed: 12 (2 ULg)Efficient springback prediction based on Enhanced Assumed Strain Elements; Papeleux, Luc ; Ponthot, Jean-Philippe in Proceedings of COMPLAS 2003, VII International Conference on Computational Plasticity. Fundamentals and Applications (2003, April) Detailed reference viewed: 7 (2 ULg)Combined implicit/explicit time integration algorithms for crashworthiness analysis and metal forming simulationNoels, Ludovic ; Stainier, Laurent ; Ponthot, Jean-Philippe in Proceedings of IMPLAST'2003, 8th International Symposium on Plasticity and Impact Mechanics (2003, March) Detailed reference viewed: 14 (1 ULg)Identification of elastoplastic model parameters in large deformation problems using gamma methodsJeunechamps, Pierre-Paul ; ; et alin Proceedings of the 5th World Congress on Structural and Multidisciplinary Optimization (2003) This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the ... [more ▼] This paper reports on preliminary results of parameter identification problems in finite element non-linear analyses such as metal forming simulations. Two approaches are compared. The first one is the classic Levenberg-Marquardt algorithm. The second one is a trust-region algorithm based on a quadratic model. The two algorithms are compared on two cases, one of them being an actuel experiment. [less ▲] Detailed reference viewed: 54 (13 ULg)Parameter identification for inverse problems in metal forming simulation; Ponthot, Jean-Philippe ; Hogge, Michel in Proceedings of FIELD ANALYSIS FOR DETERMINATION OF MATERIAL PARAMETERS. EXPERIMENTAL AND NUMERICAL ASPECTS (2003) Detailed reference viewed: 21 (1 ULg)Heat generation and transfer due to friction and plastic dissipation - a coupled thermomechanical approach; Ponthot, Jean-Philippe in Proceedings of HEFAT 2003, 2nd International conference on Heat Transfer, Fluid Mechanics and Thermodynamics (2003) Detailed reference viewed: 28 (1 ULg)A new formulation of internal forces for non-linear hypoelastic constitutive models verifying conservation lawsNoels, Ludovic ; Stainier, Laurent ; Ponthot, Jean-Philippe et alin Bathe, K. J. (Ed.) Second MIT Conference on Fluid and Solid Mechanics (2003) This paper proposes a new formulation of the internal forces for hypoelastic constitutive models ensuring that the elastic work of deformation can be restored by the scheme. Moreover, we demonstrate that ... [more ▼] This paper proposes a new formulation of the internal forces for hypoelastic constitutive models ensuring that the elastic work of deformation can be restored by the scheme. Moreover, we demonstrate that the work of the plastic deformation is positive and consistent with the material model. [less ▲] Detailed reference viewed: 16 (4 ULg)Optimization methods for parameter identification of constitutive models in finite viscoplasticity and damageStainier, Laurent ; ; Ponthot, Jean-Philippe in Proceedings of PLASTICITY 2003 (2003) Detailed reference viewed: 5 (1 ULg)Caracterization del comportamiento mecanico de aceros para embuticion profunda; ; Ponthot, Jean-Philippe in Proceedings of the joint conference Jornadas SAM, el Congreso Nacional de Metalurgia y Materiales de Chile (2003) Detailed reference viewed: 15 (1 ULg)Numerical simulation of Springback using enhanced assumed strain elements; Papeleux, Luc ; Ponthot, Jean-Philippe in Proceedings of AMPT 2003, Advances in Materials and Processing Technologies (2003) Detailed reference viewed: 6 (1 ULg)Efficient algorithmic approach for mixed lubrication in cold rolling; Ponthot, Jean-Philippe ; et alin Proceedings of AMPT 2003, Advances in Materials and Processing Technologies (2003) Detailed reference viewed: 5 (1 ULg)Nouveau concept algorithmique pour un modèle de laminage à froid en régime mixte; Ponthot, Jean-Philippe ; et alin Proceedings of the 6ème colloque national en calcul des structures (2003) Detailed reference viewed: 11 (1 ULg)New algorithm concept for a model of mixed lubrication in cold rolling; Ponthot, Jean-Philippe ; et alin Proceedings of METEC 2003, European Rolling Conference (2003) Detailed reference viewed: 15 (1 ULg)Un nouveau schéma d'intégration conservatif pour des modèles constitutifs hypoélastiques irréversibles.Noels, Ludovic ; Stainier, Laurent ; Ponthot, Jean-Philippe in Potier-Ferry, M.; Bonnet, M.; Bignonnet, A. (Eds.) Actes du Sixième Colloque National en Calcul des Structures (2003) Ce travail propose une nouvelle évaluation des forces internes pour les modèles constitutifs hypoélastiques irréversibles dans le cadre de la méthode des éléments-finis en grandes transformations. Nous ... [more ▼] Ce travail propose une nouvelle évaluation des forces internes pour les modèles constitutifs hypoélastiques irréversibles dans le cadre de la méthode des éléments-finis en grandes transformations. Nous démontrons que cette expression des forces internes utilisée avec un schéma d'intégration du point milieu conduit à un algorithme d'intégration consistant avec les lois de la thermodynamique. [less ▲] Detailed reference viewed: 45 (1 ULg)Numerical Simulation of Viscoplastic and Frictional Heating during Finite Deformation of Metal. Part II: Applications; Ponthot, Jean-Philippe in Journal of Engineering Mechanics (2002), Vol. 128 In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate ... [more ▼] In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate finite anisothermal deformation of solids and thermal field evolution due to viscoplastic and frictional heating. [less ▲] Detailed reference viewed: 9 (0 ULg)Numerical simulation of viscoplastic and frictional heating during finite deformation of metal. Part I: Theory; Ponthot, Jean-Philippe in Journal of Engineering Mechanics (2002), 128(11), 1215-1221 In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate ... [more ▼] In this paper we will apply the theoretical framework developed in Part I to various metal forming processes. These numerical simulations are exposed showing the capability of the formulation to simulate finite anisothermal deformation of solids and thermal field evolution due to viscoplastic and frictional heating. [less ▲] Detailed reference viewed: 7 (0 ULg)Simulation of Springback with Enhanced Assumed Strain Elements; ; Papeleux, Luc et alin Proceedings of NUMISHEET 2002 (2002, October) Detailed reference viewed: 16 (1 ULg) |
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