Abstract
Using the nominal structural stress, which is a parameter for assessing the fatigue life of spot welded structures, the effect on fatigue life of changes in the spot weld location, and variations in the plate thickness and nugget diameter, were investigated. With an LP model of a spot welded structure, if the weld locations fluctuate in the flange width direction, the nominal structural stress σns changes significantly, but if the weld locations fluctuate in the pitch direction, the nominal structural stress σns is almost constant and the effect is small. Fluctuations of the weld location in the flange width direction results in significant fluctuations of the fatigue life. With the TS, the fatigue life fluctuates by ±22.8% when the plate thickness varies by ±5%, and if the nugget diameter varies by ±5% about 5 mm, the fatigue life fluctuates by ±10.7%.
