혼합모드 단일과대하중 하에서 피로균열 전파거동의 예측

Prediction of Fatigue Crack Propagation Behavior Under Mixed-Mode Single Overload

In this study, experiments were tried on the mixed-mode I+II single overloading model which changes the loading mode of overload and fatigue load. Aspects of deformation field in front of the crack which is formed by mixed-mode I+II single overloading were experimentally studied. Then the shape and size of mixed-mode plastic zone were approximately calculated. The propagation behavior of fatigue crack was examined under the test conditions combined by changing the loading mode. The behavior of fatigue cracks were greatly affected by shapes of plastic deformation field and applying mode of fatigue load. Accuracy of prediction and evaluation for fatigue life may be improved by considering all aspects of deformation and behavior of fatigue cracks.