Kengo Anami

Methods for fatigue strength improvement by weld toe treatment

Summary This paper describes an investigation of methods for fatigue strength improvement of welded joints, such a TIG dressing, hammer peening and burr grinding. The main results may be summarised as follows. 1 A fatigue strength improvement is achieved by all treatment methods considered in the present research study. Most notably, the effect of burr grinding is not very dependent on the effective stress range and produces a strong fatigue strength improvement effect. 2 The fatigue strength improvement effect produced by TIG dressing is only found in the short crack region, and its fatigue strength improvement effect can be evaluated through consideration of the stress concentration reducing effect due to weld toe shape improvement. 3 The fatigue strength improvement effect produced by hammer peening strongly depends on the stress range. Little such effect is found in the Nc fatigue crack initiation region adopted in the present research study. In the Np fatigue crack propagation region, however, a stro...