Efficacy of singly curved thin piezo transducers for structural health monitoring and energy harvesting for RC structures

Abstract

Piezoelectric materials have secured a significant place in the field of structural health monitoring (SHM) and energy harvesting over the past two decades. These materials are available in several forms and configurations, the efficacy of especially curved configurations is still unexplored. This article investigates, both experimentally and numerically, the potency of the curved configuration of the piezo transducers over the straight configuration when embedded in reinforced concrete (RC) structures for energy harvesting and SHM. The study consists of the comparative analysis of (a) open-circuit voltage generated across the piezo transducers; (b) the power developed under the impedance matching conditions; and (c) the potential of power storage into capacitors for both configurations. The article also experimentally examines the hitherto unexplored damage detection capability of the curved piezo transducers by the electro-mechanical impedance (EMI) technique. Results clearly demonstrate that curved piezo transducers exhibit better performance in comparison to straight configurations for both structural health monitoring and energy harvesting. A finite element (FE) analysis is also performed through a 3-D model of the real-life-sized RC beam with straight and curved piezo transducers embedded inside to evaluate the various parameters such as the angle of bend, the thickness, the number of elements and the position of placement of the curved transducers for energy harvesting. The FE simulations reveal an optimum range of the angle of bend as 130 to 160 degrees. There is a substantial impact of the increase in thickness of the transducers for energy harvesting in terms of its open-circuit voltage. The numerical analysis also suggests that the optimum position of placement of the piezo transducers is towards the top or bottom of the beam cross-section. The outcomes of the experimental and numerical investigations are very pivotal for the implementation of curved piezo transducers in real-life RC structures for improved energy harvesting and structural health monitoring.