Fatigue assessment of out-of-plane attachments with various angles by using local stress approaches

Abstract

In order to investigate the effect of the angle between principal stress direction and weld attachment on the fatigue behavior, crack initiation points and fatigue strengths have been examined by using the fatigue test results of out-of-plane attachments with various angles under uniaxial loading. As fatigue assessment methods, the nominal stress approach, the structural hot spot stress approach and the effective notch stress approach are used. It is possible to find fatigue crack initiation points by using the effective notch stress approach, regardless of the angle between principal stress direction and weld attachment. The effect of the angle between principal stress direction and weld attachment on the fatigue crack initiation life cannot be considered when the nominal stress approach and the structural hot spot stress approach are used. However, by using the effective notch stress approach, it is possible to consider the effect of the angle on the crack initiation life.