高温合金材料循环相关和时间相关热机械疲劳循环性能模拟

从平衡热力学不可逆系统出发，用非线性粘弹塑性运动强化莱模拟高温合金材料的应变控制热机械疲劳循环特性。讨论了温度变化和应变循环的相位关系，循环相关和时间相关热机械疲劳损伤机制，蠕变和疲劳间的相互作用。在建立本构关系和状态方程时，均考虑了温度变化所产生的影响。

CYCLIC BEHAVIOR IDENTIFICATION OF CYCLIC DEPENDENT AND TIME DEPENDENT THERMOMECHANICAL FATIGUE ON HIGH TEMPERATURE ALLOYS

This paper is devoted to describe the cyclic behavior of strain controlled thermomechanical fatigue (TMF) of high temperature alloys by a nonlinear kinematic hardening model based on a irreversible thermodynamic system. The relationship between variable temperature and cyclic strain, the damage mechanics of cyclic dependent and time dependent TMF, the reaction between fatigue and creep were discussed. It is necessary to consider the effect of cyclic temperature in establishing constitutive relation. In identifying parameters of the model, isothermal mechanic and fatigue data were applied. The thermomechanical fatigue behavior described by isothermal fatigue data gives the possibility of developing the TMF lifetime prediction technique.