基于NOFRF裂纹转子非线性频谱分析

NONLINEAR FREQUENCY SPECTRAL ANALYSIS OF CRACKED ROTOR BASED ON NOFRF

建立了裂纹转子非线性逼近模型,论述了非线性输出频域响应函数(NOFRF)及其非线性频谱分析理论,基于该理论对裂纹转子系统的各阶NOFRF进行了仿真分析,该分析结果说明了裂纹转子系统新频域成份是如何产生的,对裂纹转子的超谐波成份和亚共振现象进行了解释,并进行了试验分析,结果表明了高阶NOFRF比一阶对转子裂纹深度更敏感,为裂纹转子的精确故障诊断提供了理论基础。

The nonlinear approximation model of cracked rotor,to explain the nonlinear phenomena,is constructed. The nonlinear output frequency response function（ NOFRF） and the theory of nonlinear frequency spectral analysis are illustrated.Based on this theory,the simulation analysis of cracked rotor is accomplished. The analysis provides insight into how new frequency generates. Additionally,the nonlinear phenomena of cracked rotor,including the generation of super-harmonic components and sub-resonances are explained. Experimental result shows that the higher order NOFRF is sensitive to the racked rotor with cracks of different depth. This research study establishes an important theory basis for accurate fault diagnosis of cracked rotor.