Effect of damage initiation in laminated composites using piezoelectric patch: an investigation using AE technique

Abstract

Identification of damage at its initiation is crucial for laminated composites due to their usual brittle behavior. Acoustic emission (AE) technique is capable of identifying such an initiation of damage in real time. However, laminated composites undergo several complex damage mechanisms. These AE-based damage mode identification is a complex phenomenon, and rigorous studies are needed in this direction for assigning signature signal to a specific damage mechanism. In this regard, pencil lead break (PLB), as a tool, is capable of simulating various damage mechanisms in laminated composites. Moreover, the interface of laminated composites is the weakest region, but applying PLB in this region is impossible through experimentation. To address this problem, a numerical model of laminated carbon fiber-reinforced polymer composite is modeled where PLB is applied at the interfaces in order to investigate the damage initiation at these weakest zones. However, a full-scale model of AE sensor to capture the AE waves increases the modeling complexity and cost of computation. In this regard, a simplified modeling approach is introduced by developing a finite element model of piezoelectric patch integrated with laminated composite plate. An approach is developed to correlate the frequency contents of AE signals generated by varying the angle of PLB application with various modes of damage mechanisms in laminated composites by performing wavelet transform. The introduced methodology can be used to identify several modes of damages in laminated composites for high-end engineering applications even when there is scarcity of high-end computational facility.