Performance of integrated active fiber composites in fiber reinforced epoxy laminates

Abstract

Active fiber composite (AFC) composed of lead zirconate titanate (PZT) fibers withinterdigitated electrodes (IDEs) has been integrated into orthotropic glass fiber reinforcedplastic (GFRP) laminates to characterize the performance of AFC as a smart materialcomponent in laminated materials. Monotonic cyclic tensile loading was performed onintegrated specimens at different strain levels. The AFC output was monitored todetermine the effect of applied strain level on the AFC performance. It was found that theAFC sensitivity degraded beyond strains of 0.20% and approached a minimum at 0.50%strain. The degradation in the AFC performance appears to be attributed tothe dominating effect of PZT fiber fragmentation during testing, as opposed todepolarization. Acoustic emission (AE) monitoring was used to detect damage inlaminates during testing and was correlated with crack evidence from microscopyobservations during testing to characterize damage evolution in response to strain levels.