考虑应力松弛的涡轮盘蠕变-疲劳寿命可靠性分析方法

Reliability analysis method for creep-fatigue life of turbine discs with effect of stress relaxation

关键词:  航空发动机  涡轮盘  应力松弛  蠕变疲劳  可靠性分析

Key words:  Aircraft engine  Turbine Wheel  Stress relaxation  Creep fatigue  Reliability analysis

摘要:

提出了考虑材料蠕变应变模型参数分散性及应力松弛效应的涡轮盘蠕变-疲劳寿命可靠性分析方法。首先建立蠕变应变概率模型;然后采用响应面法分别回归蠕变和疲劳损伤函数;通过蒙特卡洛法模拟总损伤分布及寿命可靠度。同时提出给定可靠度的寿命计算方法和两种考虑应力松弛的涡轮盘蠕变-疲劳寿命可靠度分析简化方法。通过算例验证了方法的有效性。

Abstract:

Reliability analysis method for creep-fatigue life of turbine discs was proposed with effect of the scatter of material creep strain model parameter and stress relaxation.Firstly,creep strain probabilistic model was proposed.Secondly,the response surface method was used to regress creep damage function and fatigue damage function.Then,Monte-Carlo method was used to simulate the distribution of total damage and reliability.At the same time,a method for life estimating with given reliability and two convenient creep-fatigue life reliability analysis method for turbine discs with effect of stress relaxation was proposed.Finally,a numerical example was given to demonstrate the efficiency and accuracy of the method.