Structural Health Monitoring Using Wavelet Transforms


A new method of damage detection using wavelet transforms and curvature mode shapes is proposed in this paper. A damage in the structure results in changing its dynamic characteristics such as natural frequencies, damping, and mode shapes. A number of researchers have investigated structural health monitoring techniques for identifying, locating, and quantifying the damage using the changes in the dynamic response of a damaged structure. Curvature mode shape and wavelet maps are two such methods that have already been used to locate damages. These methods have some limitations in determining the exact location of the damages. We have developed a technique by combining these two methods for enhancing the sensitivity and accuracy in damage location. The mode shapes are double differentiated using the central difference approximation to obtain the curvature mode shape. Then a wavelet map is constructed for the curvature mode shape. It is shown that this method can be used to determine the location of the damages. The proposed method is applied to detect damage in an experimental lattice structure and a cantilever beam with multiple damages. The mode shapes are obtained analytically using finite element analysis and also experimentally using laser vibrometer. The experimental results obtained are satisfactory.

Meeting Name

Smart Structures and Materials 2001


Electrical and Computer Engineering

Second Department

Mechanical and Aerospace Engineering

Keywords and Phrases

Structural Health Monitoring; Wavelet Transforms; Wavelets; Damage Detection; Finite Element Methods; Lasers

Document Type

Article - Conference proceedings

Document Version


File Type





© 2001 SPIE -- The International Society for Optical Engineering, All rights reserved.

Publication Date

01 Jan 2001