Applicability of the Multiscale Model for Predicting Fatigue Strength to Short and Long Crack Problems

Abstract

A multiscale model based on micromechanics of short crack growth has been proposed and proved to be able to predict the fatigue strength of steels via experiments with thin specimens in our previous work. The present study aims to validate the applicability of our model in predicting fatigue strength in long crack problems. A camera with high resolution was set up and successfully captured the crack growth process during the fatigue test. Very good agreements for both fatigue life and crack growth process were demonstrated by comparing the experimental results and the predictions from the proposed model, indicating that our model can be served as a generalised foundation to accurately predict the fatigue behaviours of ferrite-pearlite steel for both the short and long crack growth problems.