Temperature characteristics and nonlinear calibration model of self-enabled piezoelectric geocable for infrastructure monitoring

Abstract

Sensor-enabled piezoelectric geocables (SPGCs) are used for strain and vibration monitoring of various infrastructures structures. However, as a distributed sensor, the influence of temperature on the monitoring signal of SPGCs is inevitable. This study tested the impedance change of SPGCs in static temperature-varying tests and carried out dynamic tensile tests at different temperatures. The static temperature-varying tests showed that, at temperatures ranging from -10 to 50℃, the SPGC normalized impedance change value increased with increasing temperature. At temperatures ranging from -10 to 20℃ and 20 to 50℃, the normalized impedance change value and temperature were exponentially and linearly related, respectively. Dynamic tensile tests showed that the SPGC tensile strength and yield strain decreased with increasing temperature. With increasing temperature, the SPGC voltage waveform and value changed less, while the impedance response became more sensitive. Therefore, a nonlinear calibration model of the SPGC impedance-strain effect considering the temperature effect was proposed, which can be used for strain calculation under different field ambient temperatures. The test results revealed the influence of temperature on the mechanical and monitoring performance of SPGC, providing support for further engineering applications of this technology.