Failure probability of pressure pipe with pits

Based on the plastic failure criterion in the Chinese rule of Safety Assessment for Pressure Vessels with flaws (SAPV-95), considering the pit depth as generalized strength and the pressure as generalized stress, the safety margin of pressure pipe with pits is got in this paper. A three-phase method used to calculate the reliability index is proposed, which is an iterative method with high convergence speed. Finally, the failure probability of pressure pipe with pits is calculated and the variation of it depending on average values and variation coefficients of the pit depth and the pressure is discussed.