高温合金材料循环相关热机械疲劳寿命预测

在变温非线性运动强化规律所描述的高温合金材料热机械寿命应力－应变循环特性的基础上，讨论了应变控制的循环相关热机械疲劳寿命预测技术，所建模型采用了由应变以密度表示的损伤参数，并且引入了温度损伤系数，考虑了温度变化范围以及温度循环和应变循环相位关系对疲劳寿命的影响，在确定模型的一些参数，采用等温力学试验和疲劳试验的数据，为了把等温疲劳研究成果推广到变温疲劳分析领域，开辟了新的途径。

LIFETIME PREDICTION OF CYCLIC DEPENDENT THERMOMECHANICAL FATIGUE ON HIGH TEMPERATURE ALLOYS

This paper discusses the lifetime predictive techniques of cycle dependent thermomechanical fatigue(TMF) of high temperature alloys. It is based on the stress-strain cyclic behavior described by a non-linear kinematic hardening model in a irreversible thermedynamic system. In the case of the cycle dependent fatigue. combined with a temperature damage factor, a strain energy density was deduced as a damagr parameter. The influence of the variation of temperature range and the phase between therrnal cycles and strain cycles on the fatigue life was considered. In identifying parameters of the models, isothermal fatigue test results were applied. A new method using isothermal cycle data for predicting thermomechanical fatigu life was developed.