An investigation of a fatigue model with two competing failure mechanisms

At high failure probabilities, the local model dominates in the combined model. At low failure probabilities, results are less clear. There, the local model is not accurate and the global model dominates. Using the gradient adjusted point stress as the local model and the volumetric weakest link integral as the global model gives the best overall fit to the probability of failure. It is noted that for design with respect to high failure probabilities (>20%), it is enough to use only the gradient adjusted local model.