변동모드와 변동진폭의 하중조합에 따른 피로거동의 특성

In this study to execute the fatigue tests under combination load of variable-amplitude and variable-mode, loading mode was changed in each stage of single overload model. The shape and size of residual plastic deformation field which was formed by mixed-mode overloading were measured by using the C-scan method in this test. As applying mode of single overloading changes, the deformation caused by tensile and shear loading variously showed in each applying mode. The different aspects of deformation make influence on propagation behavior of cracks under constant-amplitude fatigue loading after overloading with various modes. Hence the propagation behavior in variable-mode and variable-amplitude load model was examined by considering the effects of load interaction for propagation behavior of fatigue cracks.