A METHOD OF FATIGUE LIFE PREDICTION FOR ARC WELDED STRUCTURE

摘要

The nominal structural stress is one of the key parameters for predicting the fatigue life of spot weld. In the fatigue life prediction method for the spot welded structure using the nominal structural stress, it is important to obtain the accurate value of the nominal structural stress. Authors proposed the method to accurately obtain the nominal structural stress of spot weld from the FE analysis with coarse mesh. In this study, the method to calculate the nominal structure stress for the spot-welded structures was applied to the arc-welded structure, the nominal structure stress calculation method for the arc-welded structures was proposed. In the theoretical analysis of this proposed method, the general loads acting on the arc weld toe and the displacements around the arc weld toe and the deflections in the arc weld bead are used as the load condition and the displacement boundary condition and the forced deflections. As a result, the fatigue test data of arc welded structure was able to be arranged in a narrow bandwidth on S-N chart using the nominal structural stress calculation method.