A computational framework for predicting the effect of surface roughness in fatigue

TL;DR

This paper introduces a phase field numerical framework to predict how surface roughness affects fatigue life, accounting for stochastic surface variations and validating against experimental data.

Contribution

It presents a novel computational method to estimate the surface factor considering stochastic surface roughness effects, validated with experimental data.

Findings

Increased surface roughness reduces fatigue life.

Higher failure strengths amplify the effect of surface roughness.

Surface topology and correlation length significantly influence fatigue behavior.

Abstract

Surface roughness is a critical factor influencing the fatigue life of structural components. Its effect is commonly quantified using a correction coefficient known as the surface factor. In this paper, a phase field based numerical framework is proposed to estimate the surface factor while accounting for the stochastic nature of surface roughness. The model is validated against existing experimental data. Furthermore, we investigate the influence of key parameters on the fatigue life of rough surfaces, such as surface topology and failure strength. An important effect of surface roughness is observed when the average surface roughness increases and the correlation length of the surface profile decreases. This effect becomes more pronounced with higher failure strengths.