Damage Localization For Rigid Tied-bar Arch Bridge Based On Wavelet Analysis

Wavelet analysis is known as mathematical microscope, the multi-resolution analysis and a good ability of time-frequency analysis provides a new powerful tool for the signal processing. Based on theory and numerical simulation, this paper studies the application of wavelet analysis in damage identification systematically. It focuses on the theory of wavelet singularity detection and wavelet packet energy in the rigid tied-bar arch bridge damage localization application, the main contents are:Using wavelet packet energy rate index to achieve rigid arch bridge location of damage. Via the wavelet packet decomposition of vibration acceleration signal in different damage cases, extracting wavelet packet node energy of each band, and using wavelet packet energy rate index, successfully achieves the location of single damage and multiple damages of rigid tie bar arch bridge, and studies the ability of anti-noise, with good positioning capability when the signal to noise ratio (SNR) level is greater than 10DB. Vibration acceleration signal is easy to obtain, and with high precision, wavelet packet energy method is a good way for damage locating.Based on wavelet singularity detection theory, through Vibration signal processing to achieve rigid arch bridge location of damage. Wavelet transform can effectively detect signal singularity locations. By choosing the appropriate wavelet basis function, Modal Shifts on continuous wavelet transform, to the modal displacement difference, curvature mode, curvature mode difference of continuous wavelet transform of the rigid tied-bar arch bridge differences before and after.Wavelet transform coefficients on the multi-scale modulus maximum locations the damage of structures. Comparison of three rigid tied-bar arch bridge on the ability of damage location:The damage localization ability of Wavelet transform coefficients of the modal displacement difference is better than that of curvature mode and curvature mode difference. Sometimes,damage localization ability of wavelet transform coefficients of the curvature mode difference will misjudgment. The damage localization ability of wavelet transform coefficients of the curvature mode is relative worse. Wavelet singularity detection index is constructed by displacement.But in actual measurement, displacement error is larger.So it is difficulty to promote the apply in the Practical application.