Some Effects on Fatigue Strength

Abstract

It has been widely known for some time that the mean stress affects the fatigue strength of steel. This is distinctly evident when working with non-welded or stress-relieved welded details. Some consequences of this influence are revealed when evaluating the stress history, or when counting the cycles.In this paper, decisive influences on the plain fatigue limits or strengths are indicated, when applying a mean stress, together with the effects of both combined stress and anisotropy and the minimum stress required to grow a crack of a given length and depth.

Keywords

• alternating stress
• mean load
• notched and cracked specimen
• notched fatigue data
• reversed direct stress
• stress ratio