DAMAGE LOCALIZATION FOR CFRP-DEBONDING DEFECTS USING PIEZOELECTRIC SHM TECHNIQUES

Abstract

This study employed a piezoelectric sensors-based structural health monitoring (SHM) technique to monitor debonding defects in real-time. A carbon fiber-reinforced polymer (CFRP) concrete beam specimen was fabricated, and the debonding conditions were inflicted in three successive steps. When the damage level was increased, the electromechanical impedance and guided wave signals were measured at each different damage level from the piezoelectric sensor array already surface mounted on the CFRP. A damage metric based on the root mean square deviation (RMSD) was investigated to quantify the variations in the signals between the intact and progressive damage conditions. To improve the performance of "debonding damage localization," a new damage metric obtained by the superposition of the damage sensitive features extracted from both the impedance and guided wave signals was introduced. Polynomial curve fitting was performed using the superposed damage metric values. The location corresponding to the highest peak of the curve was determined. The location point was then compared with the actual inflicted damage points to confirm the effectiveness of the proposed damage localization technique. Further research issues are discussed for real-world implementation of the proposed approach using the above experimental results.