A Parametric Lifetime Model for the Prediction of High-Cycle Fatigue Based on Stress Level and Amplitude

The goal of this paper is to present a general parametric lifetime model for predicting fatigue behaviour at any stress level and amplitude (for example, at any combination of σ_max and σ_min pair) in the high‐cycle fatigue regime. The problem of the design of the experimental laboratory test required for such a prediction is dealt with. The surprising and relevant result is that running two groups of tests for two different constant stress levels of σ_max or σ_min is sufficient to predict the whole collection of Wöhler fields for any possible stress level. However, some combinations of tests, such as one for a fixed value of σ_max and one for a fixed value of σ_min, are shown to be insufficient. Closed formulas for obtaining any Wöhler field from the results of the experiments corresponding to the two different fixed values of σ_max or σ_min are given. Together the proposed model and lab tests allow any fatigue analysis to be performed in the current investigation. One example of application illustrates the proposed method.