Modal Parameter Identification, Based On Wavelet Transform

The signal is processed on the characteristics of multi- exculpation analysis and the ability of signal partial speciality token in both of time domain and frequency domain of wavelet transformation. Signal denoising is made by the method of ameliorating threshold denoising. The denoised signal is regard on the input data of the modal identification. And then the component modal parameter is identified by the ITD modal identification method.The following is this text core contents. (1)The method of wavelet transformation is applied to the signal denoising. And the threshold denoising method of D.L.Dohono and the I.M.Johnstone is studied mostly.(2)In consideration of the above localization and non-precision of both hard threshold denoising and soft threshold denoising,an ameliorating threshold denoising method is put forward and new threshold function is conformed.(3)The different method of threshold denoising is balanced by MATLAB software. And the advantage of this text method is materialized. (4)The modal test signal is denoised by the ameliorating threshold denoising method. It is the input data of the modal identification.(5)The component modal parameter is identified by the ITD modal identification method.(6)The component modal parameter is distilled by finite element method.The girder is an applying example of this text. Its test data is identified by this text's method and the simulation test is made by MATLAB. And then the modal identification of the girder is completed. The result is contrast on the simulation result of ANSYS software and the exactitude and validity of this text result is proved. And more the engineering practicality value of the method is present.