Standard Article

Lamb Wave-Based SHM for Laminated Composite Structures

Physical Monitoring Principles

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

  1. Constantinos Soutis

Published Online: 15 SEP 2009

DOI: 10.1002/9780470061626.shm144

Encyclopedia of Structural Health Monitoring

Encyclopedia of Structural Health Monitoring

How to Cite

Soutis, C. 2009. Lamb Wave-Based SHM for Laminated Composite Structures. Encyclopedia of Structural Health Monitoring. .

Author Information

  1. University of Sheffield, Aerospace Engineering, Sheffield, UK

Publication History

  1. Published Online: 15 SEP 2009

Abstract

This article examines the application of low-frequency Lamb waves for the detection of delaminations (interlaminar cracking) in thick composite laminates. Surface-mounted piezoelectric devices are excited with a tone burst of a few cycles generating a stress wave that propagates along the structure. Experiments carried out on composite beam specimens are discussed where wave propagation distances over 2 m are achieved and delaminations as small as 1 cm2 are successfully identified. The resonance spectrum method, which is based on the study of spectra obtained by forced mechanical resonance of samples using sine-sweep excitation, is used for measuring the Ao Lamb-mode phase velocity. Finite element (FE) analyses of wave generation and propagation in wide laminated plates are also presented. The feasibility of employing piezoelectric devices for the development of smart structures, where a small and lightweight transducer system design is required, is also demonstrated.

Keywords:

  • composite materials;
  • laminates;
  • non-destructive evaluation;
  • damage detection;
  • structural health monitoring;
  • delamination;
  • interlaminar cracking;
  • Lamb waves;
  • piezo-electric transducers;
  • low frequency;
  • finite element analysis