The Proposal of crack growth evaluation method for piping under seismic loading

Yamaguchi, Yoshihito ; Li, Y.* ; Katsuyama, Jinya  ; Onizawa, Kunio 

In this study, an effect of excessive tensile and compressive loading on the crack growth behavior of piping has been evaluated through cracked plate testing. It was observed that excessive loading had changed crack growth rate. Effect on the crack growth behavior of excessive load was evaluated focusing on a crack blunting and a stress distribution near the crack tip. The crack growth evaluation method under seismic loading was proposed. Four-point bending seismic loading tests were performed using piping specimen in order to confirm the applicability of the proposed method to the piping. It was indicated that the crack growth behavior on piping could be evaluated conservatively using the proposed method, while the crack growth behavior due to seismic loading is evaluated non-conservatively by the existing method.