Effects of piezoceramic patch size, shape, and placement on sensor performance for concrete health monitoring

Structural health monitoring (SHM) is crucial for ensuring the safety and longevity of concrete structures. Despite the widespread use of piezoelectric materials like Lead Zirconate Titanate (PZT) for monitoring, the effects of PZT patch size, shape, and placement on sensor performance have not been thoroughly examined. This study aims to fill this gap by investigating how these factors influence the sensitivity and accuracy of piezoelectric sensors in concrete health monitoring. The sensitivity of the signal amplitude-frequency relationship to variations in the dimensions of the PZT patches is examined, with a focus on changes in the actuator or receiver side. It was found that changes in the receiver’s PZT patch size significantly affect signal sensitivity, while the actuator’s patch size has a lesser impact. This suggests the need for more precise calibration and sensitivity analysis for receiver sensors. PZT patches of the same size, whether embedded within concrete structures or surface-mounted, produce similar responses at low frequencies (below 50 kHz). However, at higher frequencies (above 50 kHz), the responses diverge markedly. Near the resonance frequency of the surface-mounted patch, significant fluctuations in the recorded signals are observed. After excluding these resonance frequencies, surface-mounted PZT patch receivers and embedded PZT patch actuators effectively detect and monitor surface cracks in concrete beams. This work provides new insights into optimizing sensor design for more reliable SHM systems and demonstrates the potential for improving concrete health monitoring practices through better sensor configurations.