Dynamic Crack Propagation and Branching under Biaxial Loading

Abstract

A photoelastic study of high-speed crack propagation and crack branching is conducted under biaxial loading conditions. Cross-type specimens fabricated from Homalite 100 are loaded in a specially designed loading fixture where loads parallel and perpendicular to the crack can be controlled independently. The experimental data obtained are analyzed using dynamic stress field equations and multiple points to obtain the instantaneous stress intensity factor K, the stress field parallel to the crack σox, the crack velocity å, the branching stress intensity factor Kbr, and the branching angle θ. The results indicate a strong influence of the sign as well as the magnitude of σox on both crack propagation and branching.