Applications of wavelet transform in detecting damages in multispan beams and plane frames

In this paper applications of the wavelet transform for detecting cracks and damages due to earthquake hazards in multi-span beams and plane frames were presented. A brief review of the wavelet transform theory is given, and the ability of wavelets to detect damage in structures after earthquake is demonstrated by means of numerical examples which are analyzed by ANSYS. The proposed method only requires the knowledge of the response of the damaged structure and no information about the original undamaged structure is required which is very handy in most practical cases. It is shown that the procedure can detect the localization of the damage by using a response signal from static or dynamic loads. Moreover, the response needs to be obtained only at the suspicious regions where it is suspected that the damage may be present. Also the effect of the supports on detecting damages where investigated. Results of the analysis show that if a suitable wavelet is selected, the method is quite capable to detect and localize the damage from the response signal in a simple way which can be very useful for retrofit of structures and bridges after earthquakes.

کلیدواژه ها:

Wavelet analysis ، Continuous wavelet transform ، Discrete wavelet transform ، Damage identification ، Crack detection ، Nondestructive methods