A high-consistency reusable PZT transducer with removable adhesive for in-situ guided wave-based structural health monitoring

Permanent adhesive-bonded Lead Zirconate Titanate (PZT) transducers are widely used to excite and sense ultrasonic guided waves in in-situ structural health monitoring (SHM). However, in certain scenarios, such as aerospace structures, permanent bonding poses challenges for long-term deployment due to high temperatures, complex wiring, and the mechanical fragility of PZT transducers. Reusable PZT transducers offer a promising solution to address these limitations. However, their broader adoption is hindered by the limitations of existing designs, including poor signal repeatability, insufficient bonding reliability, and the requirement for high-temperature installation. To overcome these challenges, this study proposes a novel reusable PZT transducer specifically designed to ensure high signal consistency and ease of reattachment. Both experimental testing and finite element simulations were conducted to optimize critical parameters, including the selection of removable adhesives, positioning strategies, and curing conditions. Key factors affecting signal consistency, such as positional deviations, adhesive types, curing times, and excitation frequencies, were systematically investigated. The proposed transducer, incorporating an innovative structural design, precise positioning, optimized adhesive selection, and refined operational procedures, exhibits excellent signal repeatability across multiple reuse cycles. This work provides a flexible, reliable, and efficient solution for guided wave-based in-situ SHM applications.