A Probabilistic Mechanical Model for Simulating the Fatigue Failure Process in Metals

A model for simulating fatigue damage accumulation and the fatigue failure process in metals is presented. The simulation is achieved by modeling material behavior with a series of nonlinear mechanical springs with randomized behavior. With each applied stress, a certain number of springs rupture. The damage accumulation process is modeled by the number of springs that have ruptured during the entire stress application cycle. When a sufficiently large number of springs rupture, the entire system is considered to have failed. This constitutes fatigue failure. This article follows two previous publications by the first two authors and extends the model further by incorporating additional random variables, investigating the significance of uncertainty in the spring behavior and simulation of the hysteresis behavior of metals during the fatigue damage accumulation process. Results similar to (1) the Wöhler S—N curve and (2) the hysteresis loss versus the number of stress cycle relationship, observed in laboratory testing of metal specimens, are presented.