高转速压气机转子叶片的动应力测试与动力学设计评估 *

Vibration Stress Test and Dynamical Evaluation for High Rotational Speed Compressor Blades Through Numerical and Experimental Method

关键词:  压气机叶片  振动特性  有限元分析  动应力测试

Key words:  Compressor blade  Vibration characteristics  Finite element analysis  Stress tests during operation

摘要:

为评估高转速压气机转子叶片的振动特性和工作可靠性，利用有限元计算、固有模态测试与动应力试验相结合的方法对叶片振动特性进行了研究。误差分析表明:数值计算与模态试验获得的相对误差不大于4%，动应力测试在高于43kr/min时误差会显著增大，应使用试验数据验证数值计算规律和校正低转速时动频值的方法，以获得可靠的分析结果。研究结果表明:只有转速3倍频与4倍频激起的叶片一弯共振响应较为突出，但这两个共振点均远低于慢车转速，而理论分析得到的工作转速附近共振点的叶片振动应力很小，不会引起叶片的破坏性振动，叶片满足动力学设计要求。

Abstract:

The dynamical characteristics were investigated through finite element analysis，natural mode experiments and dynamical stress tests，in order to evaluate the reliability of a certain high rotation speed compressor blade. The error analysis shows that the relative errors between calculation and modal tests were less than 4%，while the test errors for the dynamical stress tests increased rapidly when the rotation speed was higher than 43kr/min. It highlights the necessity to use the vibration stress obtained by the tests during operation to correct the calculation results to evaluate the reliability of the blades efficiently. The research indicates，only the responses at first bending mode caused by the 3 times and 4 times of rotation speed were obvious，however the two resonance points were lower than and far from the idle rotation speed，and the vibration stresses caused by the other resonance points obtained by theoretical results were small and would not lead to any serious damage for the blade.