Failure bending moment of pipes containing multiple circumferential flaws with complex shape

複数複雑形状の周方向亀裂を有する配管の破壊曲げモーメント

Li, Y. ; 東 喜三郎*; 長谷川 邦夫

Li, Y.; Azuma, Kisaburo*; Hasegawa, Kunio

Flaws due to stress corrosion cracking have been detected in piping systems in nuclear power plants. Failure bending moment of a ductile pipe containing a circumferential flaw is predicted using the net-section stress approach according to ASME Code Section XI as a limit load criterion. However, in the current code, the failure bending moment can only be adopted for a pipe containing a single circumferential flaw with constant depth. In this study, a failure estimation method for pipes containing multiple circumferential flaws with complicated shapes was proposed. Furthermore, failure experiments were performed for stainless steel pipes containing two circular circumferential flaws. The failure bending moments obtained from the experiments were compared with the estimated results. Based on the experimental results, it was concluded that the proposed failure estimation method satisfactorily represents the failure behavior of the pipes and can be applied in engineering application.