Fatigue Life Prediction at Elevated Temperature under Low – High and High – Low Loading Based OnMechanical Properties Damage Model

Abstract

In this work, an experimental study was carried to obtain the fatigueaccumulation damage for aluminum alloy, 2024-T4 under rotating bending loadingand stress ratio R= -1. The experiments were done at RT(room temperature) ,25oC,and 200oC. A modified damage stress model was suggested to predict the fatiguelife under elevated temperature which has been formulated to take into account thedamage at different load levels. The present model results were compared with theexperimental results and those calculated by the most fatigue damage model usedin fatigue (Miners rule). The comparison showed that the present model presentsreasonable factor of safety while Miner model sometimes gave a factor of safetyclose to unity.