Damage Detection Of Prefabricated Walls (Panel 3D Plates) Based On Wavelet Transform Detection Algorithm

A large number of structures experience minor damage in some elements during operation, therefore, the development of this type of damage reduces the service life of the structures and in some cases leads to total destruction. That's why, today, being assured of the health status of structures and their performance is proposed as one of the most important engineering issues. Considering the limitations of traditional damage detection methods, the methods based on changes in the vibrational characteristics of the structure have been formed. In this paper, given the modes shape of the panel prefabricated wall before and after destruction as a 2-D signal processing, the damaged zone was detected using discrete 2-D wavelet transform. At first, the panel prefabricated wall was modeled in the ABAQUS finite element software, and the frequency analysis was done to extract modal responses and was validated using modal responses of the corresponding laboratory sample. Changes in the values of natural frequencies, as well as the incompatibility of the modes shape based on the Modal Assurance Criterion (MAC) and the angle between the modes shape confirm the damage in the structure. Additionally, diagonal details from differential or summation wavelet transform analysis of the interpolated healthy and damaged modes shape (depending on the angle between the modes shape, if it approximately equals zero degree, the differential of modes shape is analyzed, and if it approximately equals 180 degree, the summation of modes shape is analyzed) indicate more irregularity of the wavelet coefficients in the damaged zone compared to other zones such that the jump relative maxima and minima in the wavelet coefficients have occurred in the damage occurrence zone.