PREDICTING METHOD OF S-N CURVE FOR WELDED STRUCTURE UNDER GENERAL RATIO OF STRESSES

The effects of geometric shape. manner of loading, ratio of stresses, residual stress, thickness of plate and the material propenies of the welded structure on the fatigue lifeare considered respectively. By means of Peterson's formula and the concept of the worst fatigue notch factor, a model of prediction of S-N curve for welded structual under general ratio of stresses is developed, A few S-N curves of welded structures have been predicted.Good agreement between the estimations and the experiments is achieved. According to the method, the fatigue experiments may be reduced greatly. Therefore it has significance for engineering application.