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Time-space analysis of a surface-bonded piezoelectric film's response with lamb wave for diagnostics

: Ali, R.


Sensors and Actuators. A 161 (2010), Nr.1-2, S.12-22
ISSN: 0924-4247
Fraunhofer IZFP ()
piezoelectric; coupled electro-mechanical dynamics; lamb wave; composites; structural health monitoring

This article is a step in the direction of statistical pattern recognition to assess the severity of the damaged state in simple engineering structures. A coupled electro-mechanical model of piezoelectric thin film to execute the dynamic analysis is proffered herein by the nearest approximation of a general real-time application of the model to sense defects in the host structure under surveillance for Structural Health Monitoring (SHM). It also tenders diagnostic measures which could best serve our purpose in terms of the L2 norm of the induced voltage and its spatial differentials. Performance of this model under timeindependent as well as time-dependent loads is looked into via illustrative examples. To visualise the differential response of the thin film model, and to depict the numerical implications of the damage, the time-independent and time-dependent characteristics of the suggested measures of damaged composite hosts are compared with that of healthy specimens, for the corresponding placement of the film on the host. An apposition of the two analyses, static and dynamic, eventuates the simulations' results portrayed for composite beam in this investigative study. The results from this case ensues a better understanding of the damage features' identification and mode conversion that takes place in the latter case of composite plate. This approach would help to place the use of piezoelectric thin films for quantitative SHM on a more solid foundation, underpinning its use in real-life situations where most of the existing structures are prestressed already.