Behavior and Law of Crack Propagation in the Dynamic-Static Superimposed Stress Field

Abstract

Abstract The aim of this study is to investigate the behavior and the law of crack propagation, particularly under the dynamic-static superimposed stress field in the poly(methyl methacrylate) specimens. We introduce a novel system of digital laser dynamic caustics experiments with a self-designed dynamic-static loading device. These specimens are divided into three groups and subjected to the static stress field, the dynamic stress field, and the stress superposition field, respectively. The conclusion can be obtained by comparing the crack length and the dynamic stress intensity factor of the main cracks during propagation under the three different stress fields. The static stress field significantly reduces the arrest toughness of the main cracks, which is the main reason for longer crack propagation.