Fatigue reliability evaluation using probability density evolution method

Probability density evolution method is extended to analysis of fatigue reliability. The joint probability density evolution equation of random parameters and fatigue damage is derived based on the principle of preservation of probability, and a finite difference algorithm in terms of TVD theory is presented. For a given damage threshold, cycle-dependent fatigue reliability can be calculated by the proposed method without assuming the probabilistic distribution of fatigue damage in advance. Two validation examples indicate that the proposed method is able to give reasonable results for constant-amplitude loading and variable-amplitude loading. The predicted fatigue reliability under constant-amplitude loading shows a considerable accuracy. In addition, reliability isolines of fatigue damage can be used to predict the fatigue life with a specified failure probability.