涡轮盘持久及低周疲劳寿命可靠性评估

摘要

为评估涡轮盘持久及低周疲劳寿命可靠性，考虑涡轮盘材料及载荷的分散性，采用响应面法与蒙特卡洛法相结合的方法，建立涡轮盘持久寿命可靠性分析模型。对给定中间以上状态工作时间400 h的涡轮盘进行持久寿命可靠度计算，并考察应力松弛效应对涡轮盘持久寿命的影响。在持久寿命可靠性分析的基础上，根据Miner线性累积损伤理论，对考虑蠕变损伤的涡轮盘低周疲劳寿命进行可靠性评估。结果表明，该涡轮盘满足400 h持久寿命、寿命安全系数1.5，及1500周低周疲劳寿命、寿命安全系数2.0的使用要求。%To predict the creep rupture and LCF life reliability of a turbine disk, considering the scatter of turbine disk material parameters and load parameters, using the response surface fitting and Monte-Carlo simulation technology, a creep rupture reliability life analysis model was constructed. The creep rupture probabilistic life of a turbine disk working 400 h was calculated. The influence of stress relaxation on the creep rupture probabilistic life was also analyzed. Based on the evaluated creep rupture reliability life and Miner linear cumulative damage theory, the creep/LCF probabilistic life was finally assessed. It turned out that the turbine disk met the design requirements of creep rupture life 400 h, safety factor 1.5 and LCF life 1 500 cycles, safety factor 2.0.