A generalized life evaluation formula for uniaxial and multiaxial static fatigue

A generalized life evaluation formula has been deduced based on damage evolution. From the comparison with the experiments in literature, it is found that the formula can well estimate fatigue life for any applied stress level. It is also found that the large scattering of experimental results can be well explained by the random initial damage, and the formula can give the mathematical expect. By introducing the concept of energy-equivalent stress, uniaxial and multiaxial static fatigue problems can be evaluated in a unified way, with the use of S–t curve obtained by uniaxial tests only.