Issue 52

J. Akbari et alii, Frattura ed Integrità Strutturale, 52 (2020) 269-280; DOI: 10.3221/IGF-ESIS.52.21 269 Multiple crack detection using wavelet transforms and energy signal techniques Jalal Akbari* Bu-Ali Sina University, Department of Civil Engineering, Hamedan, Iran, j.akbari@basu.ac.ir , https://orcid.org/0000-0001-9713-8652 Majid Ahmadifarid Laboratory of Earthquake Engineering and Structural Health Monitoring of Infrastructures ( LEESHMI ), Bu-Ali Sina University, Hamedan, Iran , mahmadifarid@gmail.com Abbas Kazemi Amiri Wind Energy and Control Centre, Department of Electric & Electronic Engineering, University of Strathclyde, Glasgow, UK abbas.kazemi-amiri@strath.ac.uk A BSTRACT . Wavelet transforms are efficient tools for structural health monitoring (SHM) and damage detection. However, these methods are encountered with some limitations in practice. Thus, signal energy analysis is used as an alternative technique for damage detection. In this paper, discrete wavelet transforms (DWT) and Teager energy operator (TEO) is applied to the curvature of the mode shapes of the beams, and the locations of the damages are identified. The results show that in comparison with the discrete wavelet transform, the signal energy operator has better performance. This superiority in detecting the damages, especially near the supports of the beam, is obvious and has enough sensitivities in low damage intensities. Additionally, the damage detection in the cases that the response data are noisy is investigated. For this purpose, by adding low-intensity noises to the curvature of the mode shapes, the abilities of the mentioned methods are evaluated. The results indicate that each method is not individually efficient in the detection of damages in noisy conditions, but the combination of them under noisy conditions is more reliable. K EYWORDS . Multiple crack detection, Wavelet transforms, Signal energy, Mode shape curvature. Citation: Akbari, J., Ahmadifarid, M., Kazemi Amiri, A., Multiple crack detection using wavelet transforms and energy signal techniques, Frattura ed Integrità Strutturale, 52 (2020) 269-280. Received: 13.01.2020 Accepted: 03.03.2020 Published: 01.04.2020 Copyright: © 2020 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.