Impedance-Based Structural Health Monitoring incorporating compensation of temperature variation effects
Diogo de Souza Rabelo1; Roberto Mendes Finzi Neto1; Valder Steffen Jr.1
1 Federal University of Uberlandia
doi:10.20906/CPS/COB-2015-1903
Resumo
The ongoing development of Structural Health Monitoring (SHM) systems has been showing to be a potential tool for reducing maintenance costs, improving life and increasing performance of engineering structures. Impedance-based SHM (ISHM) utilizes the electromechanical behavior of piezoelectric materials to detect adverse changes due to material or mechanical failures of structures. Environmental conditions such as temperature present a challenge in providing reliable diagnostics capable of distinguishing between structural damage and temperature effects. In the present study, an effective frequency shift method was implemented by using correlation analysis and experimental work both on an aluminum panel and an aircraft panel under conditions with temperature variation in order to show the performance of the ISHM method. In order to reduce temperature effects in impedance signatures, this study investigates the possibility of using several baselines to perform a more accurate diagnostic for structural integrity even under temperature variation applications by using statistical tools for determining damage metrics threshold levels. Results have shown that with this strategy, for a certain level of confidence, reliable diagnostics can be obtained with ISHM systems.
Palavras-chave: Structural Health Monitoring (SHM); Impedance; Temperature compensation