Portable System for PZT-Based Inspection of Bolted Connections
The conventional way using lead zirconate titanate (PZT) transducers (or any piezoelectric material) is to permanently install them onto the surface of the target structures to conduct related measurements. However, it requires abundant of transducers for different locations of monitoring a large structure and will be also difficult to replace defective transducers due if the structure was located in a remote environment. To overcome these difficulties, we propose a portable and noninvasive inspection device. The portable device consists of a C-shaped steel fixture, a set of two linear ball bearings and shaft rods, a pair of springs, rubber pads and waterproofing PZT transducers. The shaft rods are pulled back to allow the fixture to accommodate the inspected structure. Once the rods are released, the springs pushes the PZTs against the structure and allows effective coupling for inspection tasks. The rubber pads can absorb the opposite signal from transducers to ensure the received signals are exclusively from the generated waves traveling across the structure. Therefore, based on a pair of PZT transducers, we can perform active sensing method as one transducer generates stress waves that travel across the structure, and the waves are received by a distally placed second transducer.
Professor, Mechanical Engineering