ALE Formulation and Simulation Techniques in Integrated Computer Aided Design and Engineering System with Industrial Metal Forming Applications

摘要

A mechanical computer aided design and engineering system can be used to reduce the design-to-manufacture cycle time in metal forming process. Such a system could be built upon a solid modeling geometry engine and an efficient finite element (FE) solver. The maintenance of a high-quality mesh throughout the analysis is an essential feature of an efficient finite element simulation of large strain metal forming problems. In this paper, a mesh adaptation technique employing the Arbitrary Lagrangian-Eulerian formulation (ALE) is applied to some industrial metal forming problems. An ACIS boundary representation of the solid model is employed. This type of representation provides the necessary data for adaptive meshing techniques. To take care of large deformations, the Lagrangian types of mesh adaptation zones are used. The new mesh, which is updated at a given frequency, is found by iterating on the adaptation zones. During this process, mesh nodes are moved to new positions in order to have a more regular mesh size distribution. There are, however, cases where the ALE method needs an initial spatial mesh pattern to be able to complete the analysis. The required initial mesh depends on the plastic flow pattern of material. Examples of large strain metal forming problems illustrate the effectiveness of the method in industrial environment.