Guided-Wave Array Methods
Physical Monitoring Principles
Passive and Active Measurements with Data Analysis Approaches for Load and Damage Identification
Published Online: 15 SEP 2009
Copyright © 2009 John Wiley & Sons, Ltd. All rights reserved.
Encyclopedia of Structural Health Monitoring
How to Cite
Wilcox, P. D. 2009. Guided-Wave Array Methods. Encyclopedia of Structural Health Monitoring. .
- Published Online: 15 SEP 2009
Guided waves are an attractive mechanism for detecting localized damage in structural health monitoring (SHM) applications because the damage can be remote from sensor locations. There are various techniques for transmitting and detecting guided waves using monolithic devices, but greater flexibility and superior performance can be achieved using arrays of transducer elements in conjunction with digital signal processing. In this article, the requirements for both deployable and permanently attached guided-wave arrays are described and the differences between arrays used on one-dimensional and two-dimensional waveguides are highlighted. A distinction is made between compact arrays where the elements are in close proximity to one another, often in the same package, and sparse distributed arrays. The mathematical principles that are used to achieve mode separation and directionality with compact arrays are summarized and the practical consequences for array design are reviewed with reference to appropriate examples drawn from the literature. The final section of the article examines the somewhat different requirements of a permanently attached sparse array of sensors. Here the suppression of artifacts from structural features is the key challenge to be overcome for a successful SHM system, and it is shown how this dictates the maximum intersensor spacing that can be used.
- guided waves;
- Lamb waves;
- signal processing;
- modal selectivity;
- directional selectivity;