ABSTRACT
The study focuses on the drilling hole shape for retarding the crack propagation, on the basis of finite-element method. A lumbar-round hole was proposed, and compared with normal-round hole. The stress concentration factor (SCF) was analyzed, as well as the drilling parameters. The results show that the stress concentration at crack tip can be further decreased when comparing with the normal-round hole. The performance of lumbar-round hole can be further improved by decreasing the radius of arc. When applying the spiral transition curve to design the lumbar-round hole, a better stress distribution can be obtained, resulting in better crack retarding effects.
