A new approach for predicting the fatigue strength of steels and aluminum alloys in high & giga cycle regimes

Abstract

Since 1990s various methods have been proposed by researchers to estimate the fatigue strengths of metals at gigacycle fatigue regime (number of cycles > 108). As testing of metals in the gigacycle regime requires much time and sophisticated equipment, obtaining experimental fatigue strengths at gigacycle regime is difficult. Therefore, fatigue strength prediction methods are very important. However, the available prediction methods are complicated and require parameters which are not easily tested. Therefore, it is necessary to discover simple but reliable prediction methods that require few and easily obtainable material parameters. In this study, a new model for predicting the fatigue strength of steels at high and gigacycle fatigue regimes is first proposed. A good global relationship between the ultimate tensile strength, the fatigue strength and the number of cycles to failure is obtained after analyzing more than 80 heats of experimental results of 45 steels and 9 aluminium alloys. Using this global relationship, secondly, a model is proposed for predicting the fatigue strength of steels and alloys.