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Guided-Wave Array Methods

Physical Monitoring Principles

Passive and Active Measurements with Data Analysis Approaches for Load and Damage Identification

  1. Paul D. Wilcox

Published Online: 15 SEP 2009

DOI: 10.1002/9780470061626.shm016

Encyclopedia of Structural Health Monitoring

Encyclopedia of Structural Health Monitoring

How to Cite

Wilcox, P. D. 2009. Guided-Wave Array Methods. Encyclopedia of Structural Health Monitoring. .

Author Information

  1. University of Bristol, Department of Mechanical Engineering, Bristol, UK

Publication History

  1. Published Online: 15 SEP 2009

Abstract

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.

Keywords:

  • guided waves;
  • Lamb waves;
  • arrays;
  • signal processing;
  • imaging;
  • modal selectivity;
  • directional selectivity;
  • dispersion