Adaptive remeshing in large plastic strain with damage

Abstract

SUMMARYThe analysis of mechanical structures using the finite element method in the framework of large elastoplastic strain, needs frequent remeshing of the deformed domain during the computation. Indeed, the remeshing is due to the large geometrical distortion of finite elements and the adaptation to the physical behaviour of the solution as the plastic strain or the damage fields. This paper gives the necessary steps to remesh a mechanical structure during large elasto-plastic deformations with damage. An important part of this process concerns the geometrical and physical error estimates. The proposed method is integrated in a computational environment using the ABAQUS/Explicit solver and the BL2D-V2 adaptive mesher. After recalling the formulation of the elasto-plastic problem with damage, four types of applications using the proposed adaptive remeshing are given: orthogonal cutting, sidepressing of an infinite cylinder, blanking and backward extrusion with drilling.

Improving numerical simulation of metal forming processes using adaptive remeshing technique

“…We have chosen an error estimator based on both spatial and time value and hessian of the plastic strain. Some authors [3], [4] have proposed error estimators based on the hessian of the fields (plastic strain) and on local deviation of the solution surface using tangent plane. We experienced that the estimation of the derivatives had to be weighted by the value itself especially when damage occurs.…”

2D adaptive mesh methodology for the simulation of metal forming processes with damage

“…Many authors have proposed different error estimators based on different physical consideration [1,2,4,7,12,28]. The mesh size, all over the domain, can be derived in a first step from geometrical considerations.…”

“…The difficulties of the remeshing when large deformations occur with cracking occurrence, explain why a number of other have proposed alternative solutions such as XFEM or ALE Formulations [20]. When dealing with mesh adaptation in elastoplasticity or viscoplasticity, while using appropriate local criteria to remove cracked elements, some works have been published [1,4,7,10,[14][15][16]26]. A 2D adaptive meshing procedure for metal forming by large plastic deformation has been proposed by using a linear triangular elements and the procedure has been carried out on a number of examples [4].…”

“…When dealing with mesh adaptation in elastoplasticity or viscoplasticity, while using appropriate local criteria to remove cracked elements, some works have been published [1,4,7,10,[14][15][16]26]. A 2D adaptive meshing procedure for metal forming by large plastic deformation has been proposed by using a linear triangular elements and the procedure has been carried out on a number of examples [4]. The experience shows that the basic properties of the linear elements (interpolation function, prediction of the hydrostatic pressure) may lead to some inaccuracies when high non-linearities (necking, ….)…”

Towards an optimization methodology of a rough forged part taking into account ductile damage

“…An adaptive meshing and remeshing procedure using BL2D adaptive mesher is used in connection with ABAQUS solver in order to enhance the numerical efficiency [22,24]. For the simulation of 2D metal working processes, a special procedure (schell script) has been developed in order to execute automatically ABAQUS step by step together with adaptive meshing methodology [5,10].…”