【摘要】 利用HHT方法分析了线性SDOF体系在共振状态下的强迫动力响应,系统地研究了线性SDOF体系在简谐波、线性调频波与正弦调频波输入下处于共振状态时结构动力响应的H ilbert谱与本征模态函数的特征,并且将H ilbert谱、Morlet小波谱及Fourier幅值谱所蕴含的物理意义及分辨率特性进行了比较。研究结果表明,与Fourier幅值谱相比,H ilbert谱在刻画非平稳时程的某些时变特征方面更加直观,其物理意义更加明确,而与Morlet小波谱相比H ilbert谱则具有较高的分辨率。更多还原

【Abstract】 By Hilbert-Huang Transform(HHT),the forced dynamic response of a linear SDOF system in the resonant state is analyzed,and the characteristics of the Hilbert spectra and the intrinsic mode functions of the structural dynamic responses under the inputs of harmonic,linearly-frequency-modulated,and sinusoidally-frequency-modulated waves are systematically studied.The physical significances embedded in as well as the resolution characteristics of the Hilbert spectrum,the Fourier amplitude spectrum,and the Morlet wavelet spectrum are compared.It is demonstrated that,as compared with Fourier amplitude spectrum,Hilbert spectrum is more direct in describing some time-dependent characteristics of non-stationary time history,with its physical significance being clearer;while as compared with the Morlet wavelet spectrum,the Hilbert spectrum has higher resolution.更多还原