Normalized Life Prediction for High Temperature Materials Under Creep-Fatigue Interaction Conditions

摘要

A new normalized life prediction function based on a model in terms of stress relaxation during hold time underrncreep-fatigue condition is proposed. From the concept that the reduction of fatigue life with hold is due to the creep effectrnof stress relaxation, the relaxed stress range is suggested to be a creep-fatigue damage function. It is shown that the creepfatiguerndata satisfy the applicability of the normalized life relation model. Accordingly, using this life prediction model,rnone may realize that all the Coffin-Manson plots at the various levels of hold time under strain-controlled creep-fatiguerntests can be normalized to make one master curve.