基于热固振耦合的某附件壳体蠕变-热疲劳寿命预测方法

A Creep Thermal Fatigue Life Prediction Method for an Accessory Shell Based on the Coupling of Thermosetting Vibration

提出一种基于热固振耦合的某附件壳体蠕变-热疲劳寿命预测方法,主要是基于ANSYS-Fluent模块进行流固热耦合,仿真结果得到的附件壳体温度场分布并通过实测数据进行结果验证,再通过温度场数据传递途径结合ANSYS-Workbench模块进行附件壳体热固振耦合仿真得到壳体应力应变场,然后基于线性累计损伤理论耦合附件壳体蠕变持久寿命和热疲劳寿命,最终得到其蠕变-热疲劳寿命预测结果。针对附件壳体,一方面对比分析了单纯热疲劳寿命(41 063个循环寿命)与蠕变-热疲劳(39 054个循环寿命),通过结果得知航空发动机附件系统高热环境下蠕变作用对附件壳体热疲劳寿命是存在显著影响的;另一方面对比分析了基于稳态温度场的蠕变-热疲劳(23 334个循环寿命)与基于瞬态温度场(考虑温变速率)的蠕变-热疲劳(24 545个循环寿命),结果表明温变速率在一定程度上影响航空发动机附件系统结构的蠕变-热疲劳寿命。

A creep thermal fatigue life prediction method for an accessory shell based on the coupling of thermosetting vibration is proposed in this paper.The distribution of the temperature filed of the accessory shell obtained by the ANSYS-Fluent module is based on the simulation results of the fluid solid heat coupling,and the results are verified by the measured data.The stress and strain field of the shell is obtained by using the temperature field data transfer approach and the ANSYS-Workbench module to simulate the thermal solid vibration coupling of the accessory shell,and coupled with the linear cumulative damage theory,the creep rupture life and thermal fatigue life of the accessory shell are coupled,obtaining the creep thermal fatigue life prediction results.On the one hand,the differences between pure thermal fatigue life(41 063 cycle life)and creep thermal fatigue life(39 054 cycle life)are compared and analyzed.The results show that the high thermal creep in the aero engine accessory system has a significant effect on the thermal fatigue life of the accessory shell.On the other hand,the creep thermal fatigue(23 334 cycle life)based on steady-state temperature field and the creep thermal fatigue(24 545 cycle life)based on transient temperature field(considering temperature and variable rate)are compared and analyzed.The results show that the temperature change rate affects the creep thermal fatigue life in the aero engine accessory system to a certain extent.