Damage Prognosis of Plain Concrete Under Low-Cycle Fatigue Using Piezo-Based Concrete Vibration Sensors

摘要

The recent advent of smart materials in structural health monitoring (SHM) has paved the path for research as well as varied applications of piezo-sensors in the field of engineering. As a smart material, lead-zirconatetitanate (PZT) has proven to be an indispensable tool for SHM due to its easy availability in varying sizes and shapes, cost-effectiveness, high damage sensitivity and ease of installation. Existing research shows that PZT sensors, coupled with the electromechanical impedance (EMI) technique, can identify as well as quantify the damages induced in concrete and metals with appreciable accuracy. The study presented here employs the admittance signatures from the PZT sensors to monitor the accumulating damage in plain concrete specimens under low-cycle fatigue loading. PZT patches in the form of embeddable concrete vibration sensors (CVSs) are used for sensing purposes. Three cube specimens of size 150 mm were pre-pared: two cubes with single embedded CVS (acting in self-sensing mode) and one with a pair of CVS. The specimens were subjected to loading and unloading cycles until failure using a 3000 kN compressive testing machine. Admittance signatures were recorded from the CVS using a LCR meter at various damage stages. These signatures were then analyzed, and the root-mean-square deviation (RMSD) plots were generated to get a full damage profile of the specimens. The results reflect the effectiveness of the PZT sensors to identify the fatigue-induced damages in the concrete using PZT sensors.