Effect of thermal activation energy on dislocation emission from an elliptically blunted crack tip

Thermal activation processes are of fundamental importance for the understanding and modeling the strength of structural materials. In this paper, the effect of thermal activation energy on dislocation emission from an elliptically blunted crack tip is researched. Critical stress intensity factors are calculated for an edge dislocation emission from an elliptically blunted crack under mode I and mode II loading conditions at high temperature. The results show that the impact of thermal activation processes is remarkable, the value of the critical stress intensity factor for dislocation emission decreases at high temperature, which means the applied loads for dislocation emission will decrease with increment of temperature.