Flexural Damage Evaluation in Fiber Reinforced Concrete Beams Using a PZT-Based Health Monitoring System

Recently, the usage of piezoelectric transducers for structural health monitoring (SHM) and damage diagnosis has received increasing attention. However, the effectiveness and accuracy of SHM methods are achieved to the greatest extent, not only by quantifying the level of the potential damage but also by the damage localization. In this work, a developed wireless impedance/admittance monitoring system (WiAMS) utilizes the frequency response measurements of an array of external epoxy-bonded small-sized lead piezoelectric zirconate titanate (PZT) patches to the surface of the tested specimens to identify and localize the flexural crack. The tested beams made of fiber reinforced concrete (FRC) were subjected to a four-point bending test under repeatable flexural loading (loading, unloading, reloading). Quantification and evaluation of the flexural damage were achieved using the frequency signal measurements of the PZT transducers installed in predefined locations of the specimen and statistical damage indices. Overall, the results indicated that the proposed methodology, using the proposed SHM system and an array of carefully placed PZT transducers, could effectively detect and localize potential flexural cracking of FRC structural members with high reliability.