Prediction of low cycle fatigue lives of low alloy steels

Abstract

An assessment of low cycle fatigue data was conducted in this paper with two new life prediction methods. A phenomenological method was developed that accounts for the flow characteristics as a result of loading in terms of dynamic viscosity. The other method is a statistical method known as Diercks equation that has been used as a "first approximation" of low cycle fatigue behavior of steels in the literature. The Diercks equation has been modified in this paper and life prediction analyses were conducted and compared against the other method. The phenomenological method predicted low cycle fatigue lives conservatively under different temperatures and strain rates whereas, modified Diercks equation had several limitations that were identified in this paper. Both the methods were found to correlate the low cycle fatigue data within the acceptable band of ± × 2.