基于等效试验的蠕变-热疲劳寿命预测方法

 以往的蠕变疲劳寿命预测方法主要是针对蠕变-热机械疲劳提出的，一般不能很好应用于蠕变-热疲劳。由于蠕变 热疲劳试验周期很长，故寿命预测所需的失效数据难以得到。考虑材料的双线性随动强化和蠕变特性，深入研究了蠕变 热疲劳过程中应力和应变的规律。据此，提出把蠕变-热疲劳等效为恒定应力幅和平均应力的热 机械疲劳的寿命预测方法。由于热-机械疲劳试验不需保温时间，所需的试验装置简单、效率高，因此该方法有较好的应用前景。

A Creep-thermal Fatigue Life Prediction Method Based on Equivalent Test

Previous life prediction methods of creep fatigue mainly aimed at creep thermo-mechanical fatigue,which is not quite appropriate for creep-thermal fatigue.Because of the long period of the creep-thermal fatigue test,it is difficult to get its failure data.A detailed study of the rules of stress and strain during the creep and thermal fatigue process is made by considering the bilinear kinematic hardening and creep characteristic of the material,and a method for life prediction is proposed by equaling the creep-thermal fatigue to the thermo-mechanical fatigue of constant stress amplitude and mean stress.Since no insulating time is required,this method is effective and simple in the requirement of equipment.Consequently,it may have broad application in future.