Two-dimensional Wavelet Mapping Techniques for Damage Detection in Structural Systems

Abstract

Application of the wavelet transforms on the measured vibration data provides a new tool for the damage detection analysis of the two-dimensional structural systems. In this paper, a novel two-dimensional wavelet mapping technique for damage detection based on the wavelet transforms and residual mode shapes are proposed. After vibration data was collected, wavelet de-noising shrinkage was performed in order to reduce measurement noise. By performing wavelet decomposition of the residuals of mode shapes and by taking only detail coefficients, wavelet energy maps are constructed for all decomposition levels. The orthogonal property of the wavelet transforms has bee utilized to correlate energy at decomposition levels with the measured vibrational energy. After wavelet maps "of interest" are determined, they are mapped on top of each other to figure out damaged areas of the two-dimensional structural systems. The energy segmentation procedure is performed by using minimum homogeneity and uncertainty based thresholding methods. It has been shown that the proposed method can clearly locate the multiple damage locations on the two-dimensional structures. This method requires few sampling points, robust and independent of the type of damage or the material damaged. The proposed method is applied to detect multiple damage locations on a two-dimensional plate. The results are very satisfactory. © 2002 SPIE · 0277-786X/02/$15.00.

Department(s)

Electrical and Computer Engineering

Keywords and Phrases

2-D wavelet transforms; Damage detection; Minimum homogeneity and uncertainty based thresholding; Structural health monitoring; Wavelet mapping; Wavelet shrinkage de-noising

International Standard Serial Number (ISSN)

0277-786X

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2024 Society of Photo-optical Instrumentation Engineers, All rights reserved.

Publication Date

01 Jan 2002

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