Crack growth evaluation for cracked stainless and carbon steel pipes under large seismic cyclic loading

亀裂を有するステンレス鋼管及び炭素鋼管を対象とした地震時亀裂進展評価

山口 義仁 ; 勝山 仁哉  ; Li, Y. ; 鬼沢 邦雄 

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

Some Japanese nuclear power plants have experienced several large earthquakes beyond the design basis ground motion. In addition, cracks resulting from long-term operation have been detected in piping systems. Therefore, to assess the structure integrity of cracked pipes taking the occurrence of large earthquakes into account, it is very important to establish a crack growth evaluation method for cracked pipes that are subjected to large seismic cyclic response loading. In our previous study, we proposed an evaluation method for crack growth during large earthquakes through experimental study using small specimens and investigation using finite element analyses. In the present study, to confirm applicability of the proposed method, crack growth tests were conducted on both stainless and carbon steel pipe specimens with a circumferential through-wall crack, considering large seismic cyclic response loading with complex wave forms. The predicted crack growth values are in good agreement with the experimental results and the applicability of the proposed method was confirmed.