ABSTRACT
This paper aims to investigated the effectiveness of mixed model fatigue crack repaired by drilling-hole. The numerical approaches based on the CT specimen has been carried out. The mixed mode fatigue cracks (model I, model II and model III), were simulated, respectively, by changing the boundary and loading conditions of CT specimen. An artificial crack was simulated in the specimen, and a hole was drilled near the crack tip. Based on the numerical models, the stress variation near the drilled hole was analyzed, and different drilling-hole diameters, was also considered. It is found that, the stress concentration at crack tip can be well reduced when drilling a hole at the crack tip. When increasing the hole diameters, the maximum value near the hole edge, for model I crack, was decreased obviously, while the tendency becomes different for model II and model III crack. Therefore, it is suggested that, for the mixed model fatigue crack, the drilling-hole size is determined by the model I crack.
