An Evaluation of Fatigue Strength for Various Kinds of Spot-Welded Test Specimens

Eight kinds of the spot-welded test specimens were studied to obtain the basic fatigue data on steel sheets for car bodies.

Analytical methods such as the strain amplitude at outside and inside plates close to the nugget, the maximum nominal stress and K_θmax criteria of fracture mechanics were used. The authors propose that the ratio of strains at two points around the nugget can provide evaluation of the bending load and estimation of the fatigue strength.