Probabilistic model on stochastic fatigue damage

Fatigue damage cumulating is a random variable in essence. The randomness comes from the loading process and fatigue resistance of material. Seldom have models dealing with fatigue damage cumulating considered the co-influence of the two aspects of randomness at the same time. This article has established a probabilistic distribution model of stochastic fatigue damage. In the model, stochastic stress process is interpreted by the random distribution of stress amplitude and cycles at given amplitude, and randomness of fatigue resistance of material is described by introducing a random variable of single cycle fatigue damage. This model can calculate the fatigue damage cumulating distribution after a period of stochastic loading. A solution on narrow band normal stochastic stress process is given as an example.