涡轮盘低循环疲劳的概率设计

基于涡轮盘结构的低循环疲劳设计流程,将概率设计理念融入设计过程中,提出了涡轮盘低循环疲劳的概率设计流程。首先进行涡轮盘结构的优化分析,其中以确定性设计准则作为约束条件;以优化结构方案为基础,考虑参数的随机性,对涡轮盘低循环疲劳进行可靠性分析;以低循环疲劳寿命的可靠度为概率设计准则,对涡轮盘进行反复的设计和计算验证,通过修改结构尺寸完成涡轮盘低循环疲劳的概率设计。同时,根据灵敏度分析结果,讨论了设计变量的分散性对涡轮盘寿命的影响,为进一步提高结构的可靠性提供了新的研究思路。结果表明,按照概率设计观点确定的涡轮盘结构兼顾性能和可靠性,在满足可靠度的前提下降低涡轮盘的重量。同时该概率设计流程简单方便,易于工程的推广应用。

Probabilistic design of low cycle fatigue for turbine disk

The probabilistic design process of low cycle fatigue(LCF) for gas turbine disk was developed by replacing deterministic design methods.Firstly,shape optimization analysis of disk structure was studied where constraints were set on the basis of the successfully deterministic design criteria.Then,considering random parameters,LCF reliability was studied on the structure obtained from optimization analysis.The probabilistic design of LCF for turbine disk was accomplished by modifying the dimensions,in which LCF life reliability was taken as probabilistic design criterion.Lastly,the effect of random variables on the disk life was investigated through the sensitivity analysis in order to improve the component life and reliability.It is proved that probabilistic-based design can produce lower weight turbine disk by integrating well proved deterministic design methods and tools with probabilistic design techniques.Moreover,structural design on the basis of probabilistic design process is convenient and significant for engineering application.