1990 年 56 巻 523 号 p. 552-558
To clarify the through fatigue crack propagation behaviour in and around the heavily changed cross-sectioned area, crack propagation rate and the crack closure were measured for the CT specimens possessing blined holes or side grooves. The results were investigated using a stress intensity factor (SIF) calculated by the three-dimensional finite element method (3D-FEM). The main conclusions are as follows: (1) under the same SIF calculated by the 3D-FEM, the crack situated in the blind hole propagates slower than that in the plane specimen; on the other hand, the crack situated before the blind hole propagates faster: (2) the reduction of the crack propagation rate in the blind hole is based on the crack closure induced by the sudden change of the cross section.