A coupled thermo-elastic-plastic model with a modified direct iteration method in a cold extrusion process

Abstract

A thermo-elastic-plastic model in conjunction with an experimental flow stress-strain curve, is applied to a cold extrusion process. The flow stress is considered as a function of strain, strain rate, and temperature to simulate a more realistic situation. A modified iteration method is proposed to a linear piecewise continuous model to increase the accuracy and avoid divergence. The strain is calculated by Taylor's series expansion and is associated with its corresponding convergence criteria; an available scheme for the calculation of the strain rate is thus involved. In addition, a least squared method is proposed to check loading or unloading situations. An extrusion experiment is then made and the simulated loading force compared with the experimental loading force is very satisfactory.