抄録
It has been recognized that fatigue crack propagation is closely related with a crack closure caused by residual stress near the crack. So far, however, the quantitative relation between the residual stress distribution around fatigue crack and the crack closure has hardly been discussed based on the experimental facts.
In the present study, the X-ray oscillating stress measurement method was applied to measure the residual stress distribution around the fatigue crack which was generated under different conditions of stress amplitude, crack length and material. Furthermore, a linear fracture mechanics model was applied to discuss the effect of residual stress near the crack on the fatigue crack propagating rate quantitatively. The main results obtained are as follows.
It was found that the compressive residual stress measured on the surface behind the tip of fatigue crack could be estimated as the contact stress on the crack surface, and that the effective stress intensity factor range calculated by using this residual stress distribution was useful in understanding the fatigue crack propagation.
