Prediction of crack growth life 2A97-T3 lithium aluminum alloy under Mini-Twist load spectrum

Abstract

An important aspect of life analysis and damage tolerance design of modern aircraft structures is a reasonable model and method for prediction of fatigue crack growth behavior and growth life under actual flight spectrum loading. Mini-Twist load spectrum and constant amplitude crack propagation curves test have been conducted towards the 2A97-T3. Coefficients of Paris equation and Walker equation for constant amplitude crack propagation curves are given. The Wheeler retardation model and AFFDL closure model are used to predict the aboved crack growth life. The predicted results of Wheeler retardation model and AFFDL closure model agree well with the experimental results.