Modal parameters identification method based on wavelet transform and singular value decomposition

作者：Min Zhihua^*; Sun Limin; Sun Zhi; Dan Danhui

来源：Journal of Tongji University(Natural Science), 2009, 37(4): 460-465.

• Ambient excitations
• Degree of freedoms
• Modal parameters
• Modal parameters identifications
• Numerical simulations
• Parameter identification
• Response datum
• Singular values
• Singular vectors
• Structural accelerations
• Structural modal
• Structural systems
• Time invariants
• Wavelet coefficient matrixes

A novel modal parameters identification method based on wavelet transform and singular value decomposition is proposed. Assuming that the structural system is time-invariant and the ambient excitations are white noise, the covariance response of structural accelerations were calculated from response data measured at multiple locations of the structure; and wavelet transform was imposed to obtain the wavelet coefficient matrix of the covariance response. Then the singular value decomposition was adopted to decompose the wavelet coefficient matrix at each wavelet scale, and the modal parameters could be identified exactly from the singular value and singular vector. The formulations of the proposed method were derived and the method was verified by numerical simulation using 3 DOF structure. The results show that the method can be used to identify the modal parameters of multi-degree of freedom structure and the accuracy is better than that using a conventional wavelet transform method.

• 出版日期2009
• 单位同济大学