Reliability-Based Low-Cycle Fatigue Assessment for Crack-Stopping Hole

Reliability-based low-cycle fatigue assessment for crack-stopping holes in severe sea states was formulated. The time to initiate a new crack at a crack-stopping hole in severe sea states is predicted by strain-life methods. The limit state function for low-cycle fatigue assessment for a crack-stopping hole is established by taking into account the potential severest sea state the cracked structure may encounter before it is repaired. Low-cycle fatigue reliability assessment for two crack-stopping holes on the deck of a tanker is then performed for demonstrating the capability of the method developed. The effects of the return period of the potential severest sea state, radius of crack-stopping hole, and environmental severity factor on the reliability not to initiate a new crack at crack-stopping holes were investigated.