On the correlations among dynamic stress intensity factor, crack velocity and acceleration in fast fracture

Abstract

The method of caustics in combination with a Cranz-Schardin high-speed camera was utilized to study dynamic crack propagation in PMMA. Stress intensity factor KID was evaluated in the course of crack propagation which included crack acceleration, deceleration and re-acceleration in one fracture event. Crack velocity á and acceleration ä were also measured to correlate with KID, and the following findings were obtained: (1) KID was an increasing function of á, but their relation was not unique. (2) For a constant velocity á. KID was larger when the crack was decelerated than when it was accelerated. (3) KID was dependent on both á and ä, and KID for a constant acceleration ä could be uniquely related to á.