考虑榫槽/榫齿配合间隙的叶盘结构疲劳寿命稳健性优化研究 *

Research on Robust Optimization of Fatigue Life for Blade-Disk Considering Contact Gap between Tenon and Mortise

关键词:  叶盘结构  配合间隙  疲劳寿命  多目标规划  稳健性优化

Key words:  Blade-disk  Contact gap  Fatigue life  Multi-objective programming  Robust optimization

摘要:

为了更好地满足榫齿结构的设计、加工和制造需求，同时提高叶盘结构的疲劳寿命稳健性，利用有限元方法对不同配合间隙下的应力应变进行计算，揭示并分析了叶盘结构疲劳寿命随配合间隙的变化规律，综合考虑载荷、材料参数、配合间隙不确定性的情况下，利用二次多项式响应面分别建立了随机变量与叶盘疲劳寿命的近似函数关系，并结合多目标规划理想点法建立了叶盘结构疲劳寿命多目标稳健性优化模型。优化结果表明:叶片、轮盘疲劳寿命均值分别增加了3.24%和1.93%，疲劳寿命概率区间分别降低了10.13%和8.16%，叶盘结构疲劳寿命对参数变化的敏感度降低，有利于更加准确地进行寿命评估。

Abstract:

In order to satisfy with the practical requirement of tenon and mortise in design， manufacture and process， improve the dispersity of fatigue life for blade-disk at the same time， stress and strain in different contact gaps were calculated through finite element method， and variation regularity of LCF life with contact gaps was analyzed and revealed simultaneously. Approximate function relationbetween LCF life of blade-disk and random parameter was established by using quadratic polynomial Response Surface Method (RSM) considering the uncertainty of loads， material parameters and contact gaps， multi-objective robust optimization model for LCF life of blade-disk was set up by adopting multi-objective programming ideal point method. Results show that mean value of LCF life for blade and disk increased by 3.24% and 1.93%， respectively， probability interval of LCF life for blade and disk is decreased by 10.13% and 8.16%， respectively， meanwhile， the sensitivity of LCF life for blade-disk to random parameter is reduced， which has a certain significance to evaluate LCF life more accurately.