Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 51 3 2019 08 23 Detection of Damage in Simply-Supported Plates by Discrete Wavelet Transform of Reconstructed Modal Data Detection of Damage in Simply-Supported Plates by Discrete Wavelet Transform of Reconstructed Modal Data 503 522 2879 10.22060/ceej.2018.13723.5465 FA Milad Payesteh Msc graduated in Civil Engineering, Jundi-Shapur University of Technology, Dezful, Iran Morteza Aghajan Nashtaee Shahid Beheshti University 0000-0003-0327-9054 Mohammad Taheri Nasab Faculty of Civil Engineering, Jondi Shapur University of Technology, Dezful, Iran Seyed Bahram Beheshti Aval faculty member of shahid beheshti university of tehran iran Journal Article 2017 11 16 Localized singularities caused by changes in the stiffness or mass of the damaged region cannot be simply visible through modal analysis results. However, the wavelet transform of input signal can identify the location of defects by sudden changes in the spatial variation of transformed response. The aim of this research is to present a new method for damage detection in a damaged plate. Therefore, a squarely steel plate with fixed support conditions is modeled, symmetrically. The proposed method in this study is capable to detect existing defects in plates with damage ratio of 3%. In this approach, based on symmetry or asymmetry of mode shapes, the value of each point of mode shape data is respectively subtracted from or added with its symmetric point. The results demonstrat that the small defects are detected with high resolution by employing reconstructed modal data in contrast to the original mode shape data. In addition, it has been shown that less-detailed measurement can still be used provided an interpolation is used to improve the accuracy of the crack detection and decrease financial cost of structural health monitoring projects. Localized singularities caused by changes in the stiffness or mass of the damaged region cannot be simply visible through modal analysis results. However, the wavelet transform of input signal can identify the location of defects by sudden changes in the spatial variation of transformed response. The aim of this research is to present a new method for damage detection in a damaged plate. Therefore, a squarely steel plate with fixed support conditions is modeled, symmetrically. The proposed method in this study is capable to detect existing defects in plates with damage ratio of 3%. In this approach, based on symmetry or asymmetry of mode shapes, the value of each point of mode shape data is respectively subtracted from or added with its symmetric point. The results demonstrat that the small defects are detected with high resolution by employing reconstructed modal data in contrast to the original mode shape data. In addition, it has been shown that less-detailed measurement can still be used provided an interpolation is used to improve the accuracy of the crack detection and decrease financial cost of structural health monitoring projects. https://ceej.aut.ac.ir/article_2879_ec8b57b0be908301f5748fb04b0714c7.pdf