A Guided Wave Array for Structural Health Monitoring
by
Peter Cawley
RCNDE, Imperial College
Coauthors: Paul Fromme (University College, London), Paul Wilcox (University of Bristol), Mike Lowe (Imperial Coillege)

Many structures consist of large plate-like components which can suffer from severe corrosion and the development of cracks during their service life. Constant, long-term monitoring of the structural integrity could be performed using permanently attached remote sensors that run autonomously, i.e., independent of external energy supply, and transmit data about the condition of the structure wirelessly. Guided Lamb waves that propagate along the structure allow the fast inspection of large areas of a structure from a single sensor location.

A self-contained, permanently attached array for the inspection of plates has been designed and built. The array consists of a ring of piezoelectric transducer elements for the excitation and reception of the first antisymmetric Lamb wave mode A0. The properties and coupling of the transducers has been studied and optimized to achieve a high excitation amplitude and good measurement sensitivity. The development of the compact array device for the inspection of large areas with minimum power consumption, necessary for long term operation independent of external power sources, is described. The array operation and data processing schemes are shown and initial measurement results are presented.

Date received: December 11, 2003

Copyright © 2003 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # canb-16.