2017 年 26 巻 p. 157-164
Most of large frame-based welded structures are subjected to multiaxial cyclic loadings with different phases under in-service condition. However, the fatigue performance of these structures are evaluated according to the design codes based on theoretical and experimental investigations under a uniaxial loading condition. Most of these codes are based on the S-N curves approach. On the other hand, authors proposed the numerical simulation method of fatigue crack propagation histories of a cracked plate subjected in-plane biaxial loadings with phase difference of each loading component. Fracture mechanics approach was applied to establish our method. In this study, fatigue crack growth behaviour of an out-of-plane gusset welded joint under in-plane biaxial loading with two different phase conditions are investigated. The phase difference effect for fatigue crack shape evolution under in-plane biaxial loading is confirmed by measured ones. Besides, the numerical simulation method of fatigue crack growth is proposed and confirmed this method by comparisons of measured crack evolution with the numerical simulation results.