文档介绍：INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING
Int. J. Numer. Meth. Engng. 45, 801–820 (1999)
ADAPTIVE FINITE ELEMENT REMESHING IN A LARGE
DEFORMATION ANALYSIS OF METAL
POWDER FORMING
AMIR R. KHOEI∗ AND ROLAND W. LEWIS
Institute of Numerical Methods in Engineering; University of Wales Swansea; Singleton Park;
Swansea SA2 8PP; .
SUMMARY
In this paper, a general framework for the ÿnite element simulation of powder forming processes is presented.
A large displacement formulation, based on a total and updated Lagrangian formulation and an adaptive ÿnite
element strategy based on error estimates and automatic remeshing techniques are utilized. To describe the
constitutive model of the highly non-linear behaviour of powder materials, an elliptical cap model based on
a hardening rule to deÿne the dependence of the yield surface on the degree of plastic straining is applied.
The interfacial behaviour between the die and powder is modelled by using a plasticity theory of friction in
the context of an interface element formulation. Finally, the powder behaviour during paction of a
set plex shapes are analysed numerically. The simulation of the deformation is shown as well as the
distribution of relative density contours at di erent time stages. The results clearly indicate that the algorithm
makes it possible to simulate the powder forming problems eciently and automatically. Copyright ? 1999
John Wiley & Sons, Ltd.
KEY WORDS: Lagrangian formulation; error estimation; adaptive remeshing; cap model; plasticity theory of friction; inter-
face element
1. INTRODUCTION
The ÿnite element method has been widely used in the analysis of forming processes [1–3]. By
using the method, various forming conditions of non-linear behaviour, hardening, boundary friction,
boundary geometry and loading can be considered and unsteady forming processes can be simulated
for very large deformations. The analysis undoubtably plays an important part in