Philibert, M., Chen, S., Wong, V.-K., Yao, K., Soutis, C., & Gresil, M. (2021). Direct-Write Piezoelectric Transducers on Carbon-Fiber-Reinforced Polymer Structures for Exciting and Receiving Guided Ultrasonic Waves. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 68(8), 2733–2740. doi:10.1109/tuffc.2021.3073131
Advancements in the structural health monitoring (SHM) technology of composite materials are of paramount importance for early detection of critical damage. In this work, direct-write ultrasonic transducers (DWTs) were designed for the excitation and reception of selective ultrasonic guided waves and fabricated by spraying 25 μm thick piezoelectric poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TRFE)) coating with a comb-shaped electrode on carbon fiber reinforced polymer (CFRP) plates. The characteristics and performance of the ultrasonic DWTs were benchmarked with the state-of-the-art devices, discrete lead zirconate titanate (PZT) ceramic transducers surface-mounted on the same CFRP plates. The DWTs exhibited improved Lamb wave mode excitation (A0 or S0 mode) relative to the discrete PZT transducers. Moreover, high signal-to-noise ratio was obtained by effectively cancelling other modes and enhancing the directivity with the periodic comb-shaped electrode design of the DWTs, despite the smaller signal amplitudes. The enhanced directivity overcompensates for lower amplitude attenuation, making DWT a good candidate for locally monitoring critical stress hot-spot regions in the CFRP structure prone to early damage initiation. Further, it is shown that pairing a DWT sensor with a discrete PZT actuator could further achieve balanced performance in both wave mode selection and signal amplitudes, making this combination really attractive for ultrasonic SHM.
This research / project is supported by the A*STAR - Industry Alignment Fund-Pre-Positioning (IAF-PP)
Grant Reference no. : A20F5a0043
This research / project is supported by the A*STAR - SERC Strategic Funds (SSF)
Grant Reference no. : A1718g0056
This research / project is supported by the National Research Foundation, Singapore - Competitive Research Programme of Singapore
Grant Reference no. : CRP15 2015 04