摘要
基于现有的发动机叶片振动疲劳应力标定方法进行标定原理和实施方法研究。对比分析了振幅和af值标定疲劳应力的理论原理,针对高温下的发动机叶片振动疲劳试验,提出采用振幅和应变的近似线性关系将应变转化为振幅去表征,再通过高温下的弹性模量计算高温下的疲劳应力。搭建了发动机叶片振动疲劳应力标定试验系统,对某型发动机叶片分别进行了正弦和随机激励下的标定,试验结果显示两种激励方式获得的标定斜率在叶片第一阶频率处基本一致,为了使标定斜率偏差小于升降法步长,标定关系应只在第一阶频率附近使用,其使用范围不得超过第一阶频率的±1 %。研究结果可为其它航空发动机零部件振动疲劳应力标定提供参考。
Based on the existing vibration fatigue stress calibration methods of engine blade,the calibration principle and implementation method are studied.The theoretical principle of calibrating fatigue stress by amplitude and af value are compared and analyzed.For the vibration fatigue test of engine blade at high temperature,it is proposed to use the approximate linear relationship between amplitude and strain,transform the strain into amplitude for characterization,and then calculate the fatigue stress through the elastic modulus at high temperature.The engine blade vibration fatigue stress calibration test system is built,and the engine blade are calibrated under sinusoidal and random excitation respectively.The test results show that the calibration slopes obtained by the two excitation methods are basically the same at the first-order frequency of the blade.In order to make the calibration slope deviation less than the step size of the lifting method,the calibration relationship should only be used near the first-order frequency,its application range shall not exceed±1% of the first-order frequency.The research results can provide reference for vibration fatigue stress calibration of other aero-engine parts.
作者
张部声
姚瑾
王苏波
朱文龙
ZHANG Bu-sheng;YAO Jin;WANG Su-bo;ZHU Wen-long(Tianjin Aerospace Relialability Technology Co.,Ltd.,Tianjin 300462;School of Mechanical Engineering,Jiangnan University,Wuxi 214122)
出处
《环境技术》
2021年第6期111-114,125,共5页
Environmental Technology
关键词
发动机叶片
振动疲劳
疲劳应力
标定
振幅
engine blade
vibration fatigue
fatigue stress
calibration
amplitude
