References of "Jeunechamps, Pierre-Paul"
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See detailImplicit 2D numerical simulation of materials submitted to high strain rate including failure
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Proceedings of DYMAT 2009 - 9th International Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading (2009, September)

In this paper, we present a general consistent numerical formulation able to take into account strain rate and thermal effects of the material behavior. A thermomechanical implicit approach for element ... [more ▼]

In this paper, we present a general consistent numerical formulation able to take into account strain rate and thermal effects of the material behavior. A thermomechanical implicit approach for element erosion to model material failure is also presented. The numerical model will be illustrated by applications both from the metal forming and the impact domain. All these physical phenomena have been included in an implicit dynamic oriented object finite element code (implemented at LTAS-MN2L, University of Liège, Belgium) named Metafor [http://www.ltas-mnl.ulg.ac.be/dokuwiki doku.php?id=metafor:start]. [less ▲]

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See detailDamage and fracture of ductile materials submitted to high strain rates. An implicit thermomechanically coupled approach with element erosion
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Proceedings of “PACAM XI, 11th Pan-American Congress of Applied Mechanics (2009)

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See detailDamage and fracture of materials submitted to high strain rates. A thermomechanically coupled approach with element erosion
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Proceedings of “Dynamic behaviour of materials”, Workshop in memory of Prof. J.R. Klepaczko (2009)

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See detailNumerical simulation of materials submitted to high strain rates. A thermomechanical coupled approach
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Int. Conf. on Computational Methods for Coupled Problems in Science and Engineering, COUPLED PROBLEMS 2007 (2007)

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See detailNumerical simulation of large strain rate dependent J2 problems
GARCIA GARINO, A.; Ponthot, Jean-Philippe ULg; MIRASSO, A. et al

in Proceedings of ENIEF 2006, Mecanica Computational (2006, November)

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See detailAn efficient implicit approach for the thermomechanical behavior of materials submitted to high strain rates
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg

in Journal de Physique IV (2006), 134

In the present paper, three solutions are proposed to simulate fast phenomena with finite element method at best. At first, material constitutive laws of Johnson-Cook and Zerilli-Armstrong types are ... [more ▼]

In the present paper, three solutions are proposed to simulate fast phenomena with finite element method at best. At first, material constitutive laws of Johnson-Cook and Zerilli-Armstrong types are implemented. These well-known laws are efficient for the description of material behavior at high velocities, especially for material used in automotive or aeronautics industry. The second contribution of this paper is the coupling of an implicit Chung-Hulbert algorithm taking into account the inertial effects with a staggered scheme for solving the thermal problem. The last input of this paper is the use of EAS (Enhanced Assumed Strain) finite elements to better capture complex strain modes, especially bending that is not accurately evaluated with classical finite elements. These EAS finite elements are used in the scope of thermomechanical dynamic phenomena implemented in a modular C++ environment at the University of Liege in the home made software METAFOR. [less ▲]

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See detailA closed form technique to predict springback in creep age-forming
Jeunechamps, Pierre-Paul ULg; Ho, K. C.; Lin, J. et al

in International Journal of Mechanical Sciences (2006), 48(6), 621-629

An efficient numerical method has been developed and programmed to predict springback in creep age-forming (CAF) of alummium shell components. Physically based unified creep-ageing constitutive equations ... [more ▼]

An efficient numerical method has been developed and programmed to predict springback in creep age-forming (CAF) of alummium shell components. Physically based unified creep-ageing constitutive equations determined for AA7010 at 150 degrees C are used to evaluate age-hardening and creep deformation in CAF processes. The studies are mainly concentrated on the pure bending of aluminium plates. Effects of plate thickness, single and double curvature bending, ageing time and stress relaxation features on springback are investigated. It is shown that the proposed algorithm can predict springback accurately and gives a relationship between geometrical data and springback. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailAnalyse numérique des tests expérimentaux à grande vitesse de déformation
Jeunechamps, Pierre-Paul ULg; Ponthot, Jean-Philippe ULg; BOUVIER, S. et al

in 7ème Colloque National en calcul des Structures (2005)

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See detailA trust region algorithm for automatic identification of elasto-viscoplastic model parameters in metallurgical finite element model
Jeunechamps, Pierre-Paul ULg; Walmag, Jérôme; Duysinx, Pierre ULg et al

in Steel Grips 2 (2004), Supplement Metal Forming 2004

Simulation of manufacturing processes, here metal forming, has made major progresses during the last years. The virtual simulation of the manufacturing process being now quite well established, a natural ... [more ▼]

Simulation of manufacturing processes, here metal forming, has made major progresses during the last years. The virtual simulation of the manufacturing process being now quite well established, a natural step ahead consists in trying to find automatic procedures to optimize it. Another perspective is also to take care of the influence of the manufacturing constraints upon the design, which is the long term objective of the present research project. It aims at optimizing the design subject to both service constraints (stiffness and strength) and manufacturing constraints. A preliminary stage is to be able to build high fidelity digital models. Complex models require more and more material parameters for behavior laws (e.g. material constitutive and friction laws), which have to be identified numerically from experimental data. In this material parameter identification process, three steps can be identified. At first, an experimental testing is carried out. The second step consists in building a simulation model of the experiment. Finally, the unknown model parameters are determined to match the experimental data. A standard identification procedure consists in minimizing a given norm (here the Euclidean norm) of the error between the model predictions and the experimental results. Even if the identification problem is generally quasi-unconstrained, it has the same complexity as structural optimization problems because of the highly nonlinear and implicit character of the functions, which is especially amplified by the large deformation simulation analysis. In this paper, we use an approach of elastoplastic calculation by finite elements combined with two optimization algorithms: a Levenberg-Marquardt algorithm, which is rather classical in the literature for solving identification problems (see [2]) and a trust-region one (see [1]), which is a rather novel approach at least for structural problems. The results obtained with these two methods are then compared and discussed on two test cases. The first application is an academic test case to validate the identification method. The second one, the compression of a cylinder, takes into account an actual experiment. In this application, the material is assumed to be elasto-viscoplastic and described by a Norton-Hoff behavior law and an isotropic strain hardening law. The parameters to be identified are the coefficients of the Norton-Hoff law. [less ▲]

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See detailIdentification of elastoplastic model in large deformation problems
Jeunechamps, Pierre-Paul ULg; Walmag, Jérôme ULg; Delhez, Eric ULg et al

in 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 ▲]

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See detailIdentification of elastoplastic model parameters in large deformation problems using gamma methods
Jeunechamps, Pierre-Paul ULg; Walmag, J.; Mathonet, V. et al

in 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: 67 (13 ULg)