The invention relates to a
modal parameter identification method based on response
signal time-frequency joint distribution characteristics. According to the
modal parameter identification method based on the response
signal time-frequency joint distribution characteristics,
signal analysis and structural
modal parameter identification are carried out directly through a
structural vibration response. The modal parameter identification method based on the response signal time-frequency joint distribution characteristics comprises the steps of firstly carrying out complex
wavelet continuous transformation on a structural response signal, obtaining
energy distribution characteristics of various
wavelet transformation domains (a real domain, a virtual domain, a modal domain and a
phase domain), obtaining a
time average wavelet energy spectrum through a wavelet transformation coefficient, therefore carrying out quantification on selection of model orders and the scale corresponding to each order modality, on the basis, obtaining the optimum scale required by parameter identification, achieving pre-identification of modal frequency through the corresponding relation of the scale and the frequency, finally extracting a wavelet transformation coefficient slice at the specific scale, carrying out
linear fitting through an amplitude value and a phase component, and achieving structural identification of inherent frequency and a
damping ratio. As
simulation and experiment results show, even if an external incentive function is not included, accurate identification of structural modal parameters can be achieved through the modal parameter identification method based on the response signal time-frequency joint distribution characteristics.