Spall Study in Mild Steel

Abstract

The influence of inertial, thermal, and rate-sensitive effects on the void growth at high strain rate in a thermal-viscoplastic solid is investigated by means of a theoretical model proposed in the present paper. Numerical analysis of the model suggests that inertial, thermal, and rate-sensitive effects are three major factors which greatly influence the behavior of the void growth in porous ductile materials in high strain rate case. One and two-dimensional plate-impact tests of mild steel are performed. Microscopic observations of the softly recovered specimens reveal the mechanism of micro-damage. As an application of the theoretical model, the processes of one and two dimensional spallation in mild steel are successfully simulated by a finite-difference Lagrangian dynamic code in which the mathematical model presented in this paper is incorporated.