ELASTIC–PLASTIC ANALYSIS OF THE FATIGUE LIMIT FOR A MATERIAL WITH SMALL FLAWS

Abstract

Abstract Fatigue tests were carried out on mild steel with small cracks for which linear fracture mechanics is not effective. A fatigue limit criterion, based on the cyclic plastic zone size at a crack tip being a material constant at the fatigue limit, can effectively evaluate the effects of crack length and stress ratio. Regarding flaws as cracks, the theory gives fatigue limit values close to those obtained in experiments on specimens with natural defects, such as surface roughness, micro‐shrinkage cavities, inclusions etc. The effect of water corrosion was also investigated.