结构故障高阶谱诊断的一种方法

高阶谱较之功率谱有三个显著特点:(1)可用来检查过程高斯性;(2)可估计非高斯过程的相位;(3)可检查系统的非线性.高阶谱的特点使得它可用于故障诊断.本文分析了频响函数三阶谱对刚度变化的敏感度,并将它用于故障诊断.数字仿真与实物试验结果表明,本文提出的方法是可行和有效的.

A Method of structural Fault Diagnosis by Higher Order Spectrum

As compared with the power spectrum, the higher order spectrum (HOS) has three features, HOS may be used to. (1) detect the Gaussianness of a process;(2) estimate the phase of a non-Gaussian process; (3) detect the non-linearity of system. In this paper, the sensitivity of a third order spectrum of frequency response function (FRF) to the variation of structural stiffness is analysed.The HOS of FRF is introduced into the fault diagnosis. Results of the digital simulation and the specimen test show that the approach to the structural fault diagnosis presented in the paper is applicable and effective.