title: Damage detection on sudden stiffness reduction based on discrete wavelet transform.
abstract: The sudden stiffness reduction in a structure may cause the signal discontinuity in the acceleration responses close to the damage location at the damage time instant. To this end, the damage detection on sudden stiffness reduction of building structures has been actively investigated in this study. The signal discontinuity of the structural acceleration responses of an example building is extracted based on the discrete wavelet transform. It is proved that the variation of the first level detail coefficients of the wavelet transform at damage instant is linearly proportional to the magnitude of the stiffness reduction. A new damage index is proposed and implemented to detect the damage time instant, location, and severity of a structure due to a sudden change of structural stiffness. Numerical simulation using a five-story shear building under different types of excitation is carried out to assess the effectiveness and reliability of the proposed damage index for the building at different damage levels. The sensitivity of the damage index to the intensity and frequency range of measurement noise is also investigated. The made observations demonstrate that the proposed damage index can accurately identify the sudden damage events if the noise intensity is limited.
authors.affiliation: Key Laboratory of Roadway Bridge and Structural Engineering, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.affiliation: Key Laboratory of Roadway Bridge and Structural Engineering, Wuhan University of Technology, Wuhan 430070, China ; School of Architecture and Civil Engineering, Xiamen University, Xiamen 361005, China.
authors.forename: Zhi-wei
authors.initials: ZW
authors.lastname: Chen
authors.affiliation: Zhongshan Power Supply Bureau, Guangdong 528400, China.
authors.forename: Gan-jun
authors.initials: GJ
authors.lastname: Wang
authors.affiliation: Key Laboratory of Roadway Bridge and Structural Engineering, Wuhan University of Technology, Wuhan 430070, China.
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Xie
mesh_terms: D009716:Numerical Analysis, Computer-Assisted; D014732:Vibration; D058067:Wavelet Analysis