Health monitoring of steel structures using surface mountable and detachable PZT sensor

A lot of collapse in the infrastructure were reported in the last decades, hence the need for monitoring the health of the structures also arises. There are various techniques available to monitor the health of the structure, in which Electromechanical impedance (EMI) technique is one of them. In EMI technique, the PZT sensor is bonded to/embedded in the structure using epoxy. The thickness of epoxy layer used as an adhesive should be maintained as thin as possible, which cannot be achieved ideally, which introduces shear lag effect such that is, complete strain transfer cannot take place between PZT and host structure. The shear lag effect caused is one of the major drawbacks in the EMI technique and due to this effect, the damage detection sensitivity decreases. To overcome this drawback, in this study a new sensor named Surface Mounted PZT Sensor (SMPS) is proposed for the steel structure. Along with this, the performance of other sensor configurations such as conventionally bonded PZT with epoxy that is Surface Bonded PZT Sensor (SBPS) and Adhesive Covered Surface Bonded PZT Sensor (ACSBPS) are also been compared. The results show that, SMPS was working effectively and was more sensitive compared to SBPS and ACSBPS.