Evaluation of the piezoelectric and mechanical behaviors of asphalt pavements embedded with a piezoelectric energy harvester based on multiscale finite element simulations

Abstract

The piezoelectric energy harvester (PEH) has gained interest for its abilities in harnessing the wasted mechanical energies in pavement. To comprehensively evaluate the piezoelectric effectiveness of PEH under various loading and boundary conditions and further to provide necessary background for future PEH designs, numerical models of tire-pavement-PEH system were developed based on the finite element approaches. The small-scale model of the PEH was established and embedded into a large-scale pavement model to investigate its mechanical and behaviour. In addition, a duplication of the PEH model was built to simulate the piezoelectric behaviour. By transferring the deformations, the large-scale pavement model and the small-scale PEH were effectively coupled. Therefore, both the piezoelectric performance of the PEH and the mechanical responses of the entire system were able to be clearly illustrated. The simulation took into account various temperatures, buried depths, horizontal locations, load values, and traffic speeds. The results indicate that a buried depth of 2 cm can achieve the highest efficiency of energy harvesting; meanwhile, the stress concentration in asphalt layer over the PEH becomes remarkable. The horizontal offsets of the tire loading locations would induce damage in asphalt layer adjacent to the PEH. Heavier loads improve the piezoelectric performance of the PEH to a certain extent, and such improvements are related to the internal structures of the PEH. However, the increase of the load greatly induced the stress concentration behaviour surround the PEH.