Constant Amplitude Fatigue Life Assessment Models

The applications of the stress-life, local strain, linear elastic fracture mechanics, and component test models to the prediction of constant amplitude fatigue life are reviewed. Predictions of cycles to crack initiation in a component: by the stress-life and local strain models are illustrated by examples and compared to results of tests on the component. Estimation of the cycles of crack propagation to fracture of the component is demonstrated by an example of the application of linear elastic fracture mechanics. The prediction of the total life of a component by a combination of the local strain and fracture mechanics models is discussed and illustrated.