Wear of Dies of Bulk Straining According to Criteria of Low-Cycle Fatigue and Plastic Crushing

Abstract

Cyclically changing thermomechanical loads causing the stress–strain state of dies are part of the crushing mechanism of surface and crack propagation in stress concentration zones. In order to evaluate the maximum stresses causing the critical strains of a die, a mathematical model is developed making it possible to predict the durability of a die’s working parts. The durability of punches and matrixes is estimated by the average number of loading cycles up to the breakdown of the tool according to the criteria of low-cycle strength and plastic crushing.