Probabilistic simulation of fatigue damage and life scatter of metallic components

A three-dimensional (3D) finite element model (FEM) is developed to predict the progressive fatigue damage with provision for stochastic distribution of material properties. Fatigue damage model for low and high cycle fatigue considering plastic deformation is implemented in the FEM and the results are presented for Al 6061–T6, Al 7075–T6, Ti 6Al–4V and SS 316. Comparisons of the numerical and experimental results of stress-life reveal the validity of the approach. Also presented is the result of an investigation showing the effect of element types, element size, variation of material properties, and initial flaws on the randomness of fatigue life. The present fatigue damage simulation allows determining the scatter lifespan of mechanical components subjected to low and high cycle fatigue loading.

► Three-dimensional finite element model predicts progressive fatigue damage.
► Probabilistic nature of fatigue and plastically-induced damage are considered.
► Scatter feature of fatigue life with provision for initial flaws is considered.
► The model can predict the fatigue life scatter in both high- and low-cycle regimes.
► Results of predictions are in agreement with published experimental measurements.