Durability Assessment of Bonded Piezoelectric Wafer Active Sensors for Aircraft Health Monitoring Applications

Abstract

This study conducted experimental and numerical investigations on piezoelectric wafer active sensors (PWASs) bonded to an aluminum plate to assess the impact of bonding degradation on Lamb wave generation. Three surface-bonded PWASs were examined, including one intentionally bonded with a reduced adhesive to create a defective bond. Thermal cyclic aging was applied, monitoring through laser Doppler vibrometry (LDV) and static capacitance measurements. The PWAS with the initially defective bond exhibited the poorest performance over aging cycles, emphasizing the significance of the initial bond condition. As debonding progressed, modifications in electromechanical behavior were observed, leading to a reduction in wave amplitude and distortion of the generated wave field, challenging the validity of existing analytical modeling of wave-tuning curves for perfectly bonded PWASs. Both numerical simulations and experimental observations substantiated this finding. In conclusion, this study highlights the imperative of a high-integrity bond for the proper functioning of a guided wave-based structural health monitoring (SHM) system, emphasizing ongoing challenges in assessing SHM performance.

Feasibility Study for Monitoring an Ultrasonic System Using Structurally Integrated Piezoceramics

“…Teti et al present the high importance of sensor systems and possibilities of close-to-process piezoelectric sensors [19]. Furthermore, different uses of integrated sensors are presented in [20][21][22]. Eiras et al present an approach for monitoring aircraft health using bonded piezoelectric wafer sensors, while Khattak et al developed a polyvinylidene flouride (PVDF) sensor that is embedded in a metal structure and can achieve a high linearity with this approach.…”