Evaluation of Stress Distribution and Fatigue Strength of a Single Elliptical Spot-Weld Lap Joint

For the purpose of changing the stress concentration controlling its fatigue strength. An “ELLIPTICAL” spot weld was investigated by the analytical method, the finite element analysis of the stress distribution around the spot weld and related fatigue experiments.

The stress around the specimen with a flat elliptical spot weld can be lower than that a circular spot with the same area. Therefor, flat spot weld can be used for reduction of the stress concentration.

Using the maximum stress, all of experimental S-N data for the spot welded specimens with various sizes and various radius ratios fell nearly into one scatter band.