Experimental and finite element assessment of three energy harvesting prototypes for roadways

Abstract

The transportation infrastructures serve a critical societal need to rapidly move goods and people across the nation. Using these infrastructures as a source of renewable energy by harvesting them from the roadways is a novel idea that has not been fully explored yet. Highway pavements are exposed to energy-potential resources from vehicle vibrations and traffic loading strains. Energy harvesting is a process that captures unused ambient energy such as heat, vibration, stress or movement that would otherwise be lost. Piezoelectric transducers are considered materials for harvesting energy in pavement structures as they convert mechanical strain into low voltage. For this purpose, two types of piezoelectric geometry were evaluated; cylindrical disks and thin film, suitable for compression and bending state of stresses, respectively. Two prototypes including piezoelectric disks connected in series and parallel were evaluated to study the effect of loading frequency and magnitude on output power under compression. Another prototype containing thin piezoelectric film was developed to investigate the potential of energy harvesting in bending condition. Finite element (FE) analysis was conducted to simulate prototypes’ response under loading. The evaluation of the prototypes involves laboratory testing of their power output as a function of stress and FE simulation of their mechanical behavior. The results showed that the energy harvesting modules should be designed to capture vertical compressive stress in pavement instead of tensile stress. Results suggested that voltage is highly dependent on loading magnitude. It was also concluded that piezoelectric stack connected in parallel produces higher current output under similar loading conditions.