涡轮盘的损伤容限分析

本文是“断裂力学在涡轮盘上应用”课题研究的总结。研究工作紧密结合某发动机Ⅰ级涡轮盘槽底裂纹的实际问题,得出涡轮盘损伤容限设计方法。根据工程实际,提出适于涡轮盘裂纹尖端参量J积分计算的二次计算法,及确定涡轮盘临界裂纹长度a_(IC)的准则和方法。在裂纹扩展寿命计算中,采用大量实际统计数据修正计算公式,故有工程应用价值。

ANALYSIS OF DAMAGE TOLERANCE FOR TURBINE DISKS

This paper deals with the analysis and design of the damage tolerance for turbine disks. A practical design method is worked out and verified through analysing the damage tolerance of an existing engine. A "twice evaluation algorithm" for evaluating J-integral is provided, in which J is estimated in the light of the linear elastic fracture mechanics, and then a plastic correction with iterative procedure is made to obtain J. On the basis of breakdown tests and elaborate theoretical calculations, a criterion and a solution algorithm for determining the critical crack length are suggested. A method calculating residual life or turbine disk initiating cracks is provided, which is proved practical. The numerical results obtained by this method are in good agreement with the statistics of crack propagation collected from the actual turbine disks.