Numerical Simulation of Lubricated Contact between Solids in Metal Forming Processes using the Arbitrary Lagrangian Eulerian Formulation

in Simulation of Material Processing: Theory, Methods and Application: Proceedings of the 7th International Conference NUMIFORM 2001 (2001, June)

ALE Methods for Determining Stationary Solutions Metal Forming Processes

in Oñate, E.; Bugeda, G.; Suárez, B. (Eds.) Proceedings of ECCOMAS 2000/COMPLAS VI, European Congress on Computational Methods in Applied Sciences and Engineering (2000, September)

In this paper, two efficient convection algorithms are briefly presented in order to update the values stored at the Gauss point during the Eulerian step of an Arbitrary Lagrangian Eulerian computation in ... [more ▼]

In this paper, two efficient convection algorithms are briefly presented in order to update the values stored at the Gauss point during the Eulerian step of an Arbitrary Lagrangian Eulerian computation in solid mechanics. They are based on the finite volume method and on the Streamline Upwind Petrov Galerkin method. Two applications are presented : a cold rolling simulation and a drawbead simulation. [less ▲]

ALE Update Procedures for Stationary Solutions of Metal Forming Processes

in Proceedings of the 5th National Belgian Congress on Theoretical and Applied Mechanics (2000, May)

Eléments Finis de Lubrification pour la Prise en Compte du Frottement dans la Simulation de Processus de Formage des Matériaux

in Chabrand, Patrick; Jean, Michel; Raous, Michel (Eds.) Colloque National Mécamat 2000 (2000, January)

Numerical Methods for the Lubricated Contact Between Solids in Metal Forming Processes

in ECCM’99, European Conference on Computational Mechanics (1999, August)

In this paper, the lubrication problem in numerical simulation of forming processes is presented. In the case of the rolling process, the recent and complex model of Marsault for the solution of the mixed ... [more ▼]

In this paper, the lubrication problem in numerical simulation of forming processes is presented. In the case of the rolling process, the recent and complex model of Marsault for the solution of the mixed lubrication regime has been implemented and tested. This model needs the use of the finite difference method to work properly. We will discuss the advantages and the difficulties encountered when trying to solve the same problem with the finite element method in a general frame. Finally, a finite element formulation for the solution of the time dependant Reynolds’ equation coupled with the deformation of the workpiece is proposed. [less ▲]

A Symmetric Tangent Operator Recovery via Quasi-Coulomb Model for Frictional Contact Between Solids in Large Deformation Analysis

in ECCM’99, European Conference on Computational Mechanics (1999, August)

Frictional contact interfaces have to be modeled in practice when industrial problems such as metal forming operations, crashworthiness, and so on, have to be simulated. Usually a Coulomb model is used in ... [more ▼]

Frictional contact interfaces have to be modeled in practice when industrial problems such as metal forming operations, crashworthiness, and so on, have to be simulated. Usually a Coulomb model is used in order to describe the constitutive law for the frictional case. Following a standard plasticity approach to Coulomb law a non-symmetric tangent operator is found, and so a non-symmetric solver has to be used in order to take full advantage of consistent operators. With respect to symmetric ones, these non-symmetric operators lead to prohibitive computational times. However, in practice different schemes have been proposed in order to recover the symmetric operator, and consequently, use a symmetric solver. In this work an alternative approach based on an idea due to Garcia Garino and Oliver [33] is defined in order to avoid to deal with non-symmetric solvers and thus save a large amount of computational time, which renders the computational simulation more attractive to industry. Applications to metal forming simulations and crashworthiness analysis are envisaged. [less ▲]

Effective Iterative Solvers for Highly Non-Linear & Large Deformation Pressure Dependent Problems

in Van Keer, R.; Verhegghe, B.; Hogge, M. (Eds.) et al Proceedings of ACOMEN'98, Advanced Computational Methods in Engineering, part 2: Contributed papers (1998, September)

In this paper, we present a stress update scheme for non-deviatoric elastoviscoplastic models, which can be considered as an extension of the radial return method for classical plasticity. We use the ... [more ▼]

In this paper, we present a stress update scheme for non-deviatoric elastoviscoplastic models, which can be considered as an extension of the radial return method for classical plasticity. We use the unconditionally stable backward Euler scheme to obtain the viscoplastic solution at each increment. To solve the large sparse non symmetric iteration matrix, we use the GMRES method. This fast iterative solver, in conjunction with an appropriate preconditioner, can save a lot a memory and CPU time when 3D problem are considered. A comparison between direct and iterative solvers will be discussed on two applications of cold compaction of powders. [less ▲]

Iterative Solvers for Large Pressure Dependent Problems

in Huétink, J.; Baaijens, F. P. T. (Eds.) Proceedings of the Sixth International Conference on Numerical Methods in Industrial Forming Processes (1998, June)

In this paper, we present a stress update scheme for non-deviatoric elastoviscoplastic models, which can be considered as an extension of the radial return method for classical plasticity. We use the ... [more ▼]

In this paper, we present a stress update scheme for non-deviatoric elastoviscoplastic models, which can be considered as an extension of the radial return method for classical plasticity. We use the unconditionally stable backward Euler scheme to obtain the viscoplastic solution at each increment. To solve the large sparse non symmetric iteration matrix, we use the GMRES method. This fast iterative solver, in conjunction with an appropriate preconditioner, can save a lot a memory and CPU time when 3D problem are considered. A comparison between direct and iterative solvers will be discussed on two applications of cold compaction of powders. [less ▲]