Multi-physics modelling of piezoelectric pavement system for energy harvesting under traffic loading

This study aims to evaluate the field performance of the piezoelectric-based energy harvesting pavement system (PZ-EHPS) under moving traffic loads by multi-physics modelling. Finite element models (FEMs) with multiple physical interfaces were built with the close circuit system. The laboratory scale of FEM was analysed to validate the voltage output as compared to the measurements in laboratory tests. To enhance the computational efficiency of large-scale simulation, a homogenisation approach was developed to convert the piezoelectric composite layer to the homogeneous layer with equivalent mechanical and electric properties. The variations of power output patterns from the PZ-EHPS, with different geometric designs under different traffic loading levels and temperature conditions, were studied. The results show that the width of the PZ-EHPS shall match the wheel path to generate electricity and avoid energy consumption in the area uncovered by traffic loading, during the electricity transmission. The power output of the PZ-EHPS shows an exponential relationship with the increase of load magnitude from vehicles. Future studies are needed to achieve the full utilisation of each function layer for building smart pavement with multiple functions.