Mode ‡V Fatigue Crack Growth Behavior -Transition Condition of the Crack Growth Mode-
Yukiyoshi KOBAYASHI, Shoji HARADA, Yoshihito KUROSHIMA, Yasunobu FUKUDA and Ryouhei MIYOSHI
Abstract:Mode‡V fatigue crack is usually observed at the root of circumferentially notched round bar. As the crack grows in the depth direction of specimen, the growth rate of crack decreases. In this respect, crack mode transition from mode‡V to mode‡T is understood responsible. However, quantitative evaluation on crack mode transition has been hardly done. Therefore, values of stress intensity factor K‡T under mode‡V fatigue crack growth tests on a low carbon steel were calculated with using principal stress, as crack mode transition began. Then K‡T values were compared with crack growth rate curve of mode‡T. As the result, it was observed that the condition of crack mode transition was given by the crack growth rate curve of mode‡T. Key Words:Mode‡V, Crack growth, Crack mode transition, K value, J integral