DAMAGE DETECTION IN CONCRETE BEAMS UNDER IMPACT LOAD USING PIEZO SENSORS

Abstract

Over the past few years, damage detection and structural health monitoring has gained a lot of interest in the civil engineering field. It helps in analysing a system over a period of time by monitoring their changes in properties like geometrical or material, of engineering various structures. Smart materials such as lead zirconate titanate (PZT) is being widely used to detect damages in a structure with the help of electro-mechanical impedance (EMI) technique. The PZT patches uses high frequency responses to detect damage. The EMI technique uses both the direct and converse piezoelectric effect which allows the PZT sensor to act as both the actuator and the sensor. Changes in admittance signature indicates the damage and this is quantified by using root mean square deviation index (RMSD). In this study, damage detection of plain concrete beams with embedded PZT sensors under impact load are used to find the extent of damage detection properties of PZT sensors. Parametric study on height of impact, position of sensors and grade of concrete has also been done. This is further validated with the help of ANSYS software through finite element analysis. For this, velocity impact simulations have been done in ANSYS Explicit dynamics module and the behaviour of the concrete beams have been studied. From the study, it can be concluded that the RMSD percentage value and peak value of admittance signature is increasing with each impact which indicates the increase in extent of damage.. It can be concluded that EMI technique has proven to be one of the effective methods for structural health monitoring and in detecting damages.