Plastic Modifying of Dynamic Stress Intensity Factor under Impact Load

Abstract

The aim of this paper is to analyze the feasibility of calculating Dynamic Stress Intensity Factor (DSIF) considering crack propagation by plastic zone. At first, the plastic zone size is calculated and the equivalent crack can be obtained. Then based on which, the DSIF subjected to the impact load is calculated. The results showed that the DSIF after plastic modifying is obviously lower than the one calculated based on linear elastic material model. Furthermore, there is a maximum value in the time history curve of DSIF. Then, the equivalent crack propagation velocity is analyzed. The result shows that when the impact load reaches the peak value, crack propagation velocity also reaches the maximum value, and so does the DSIF.