Empirical Formula for Fatigue Strength of Singlle-Spot-Welded Joint Specimens under Tensile-Shear Repeated Load

This study intends to make clear the effects of the property of base metal, specimen width, sheet thickness and nugget diameter on the initiation life of fatigue crack and the propagation life in single-spot-welded joint specimens under tensile-shear repeated load, and using these results to establish an empirical formula according to which the ΔL-N diagram can be drawn.

It was confirmed that accuracy of the empirical formula is at considerable high level, when this formula is applied for data of hitherto published many reports, and the predicted results obtained by this formula are compared with these experimental results.