Identification of structural damage using multifunctional Bragg grating sensors: I. Theoryand implementation

Abstract

Structural health monitoring has become a respected and established discipline inengineering. Health monitoring involves the development of autonomous systems forcontinuous monitoring, inspection and damage detection of structures with minimuminvolvement of labour. The ultimate goal of structural health monitoring is to increasereliability, improve safety, enable light-weight design and reduce maintenance costs for allkinds of structures. The identification of structural damage is therefore a key issue instructural health monitoring. The scope of this paper is to present the results of testing asystem for the identification of structural damage based on fibre Bragg grating sensors.The basic idea is to use fibre Bragg gratings as acoustic receivers of ultrasonicLamb waves. The layout of such a damage identification system is introduced andits theoretical limits are studied numerically and experimentally. The set-up fordamage identification experiments is described and the results of initial experimentsintroducing damage detection based on the analysis of Lamb wave signals are presented.The results for the Bragg grating sensors are then compared to the results ofestablished technology for Lamb wave detection using piezoceramic transducers.