Experimental strain sensitivity investigations on embedded PZT patches in varying orientations

Abstract

Piezoelectric ceramic (PZT) patches are well established as dynamic strain sensors. Thin Lead Zirconate Titanate (PZT) patches have been used as strain sensors in the present study in various configurations. The property of PZT to generate voltage on application of strain also works conversely, i.e. they also develop strains on applying a voltage across their ends. It is well known that thin PZT patches, operating in d31-mode i.e. response is measured across the poling direction (dir-3) and strain is applied along longitudinal direction (dir-1) serves best for strain sensing, whereas d33-mode, i.e. both response and application of strain are measured across the poling direction is best for energy harvesting. In this study, PZT patches were tested for their responses while embedded in host structure in three different configurations i.e. horizontal (0°), vertical (90°) and inclined (45°) after embedding in a prototype RC beam, 150 × 210 × 2,000 mm in size. The results show that the 90° configuration is the best and 45° configuration is worst from strain sensing point of view.