Modeling and performance analysis of flexible pavement structure with an embedded energy harvesting module
The energy generated by moving traffic can be converted into electrical energy. A Module, composed of multiple piezoelectric units, embedded within a pavement structure represents a viable option to harvest this traffic-generated energy. The goal of this research work is to determine an optimal set of operating conditions that would maximize the efficiency of the energy harvesting module system while guaranteeing the structural integrity of the pavement structure. The objectives of this research are to find the optimum locations for the energy harvesting module within the pavement structure, identify the critical environmental conditions and material parameters that contribute to the efficiency of the module and analyze the impact of having an embedded module on the long term durability of the pavement structure. These research objectives were achieved by conducting a thorough numerical analysis. A three dimensional finite element model of the pavement-module system incorporating the effects of temperature and time dependent asphalt properties was developed. Static and dynamic simulations were carried out in the commercial software ABAQUS. The Extended Finite Element Method was used to study the surface crack propagation potential of flexible pavement structure under the influence of the module. The results suggest that the module should be placed as shallow as possible but deep enough to allow pavement rehabilitation. It should be noted that a top plate of sandwiched structured module should be rigid enough so as to distribute the stresses on wider area of the module, as it was identified that a stiff module upper plate will transmit stress in all piezoelectric elements, even when not directly underneath the tire footprint. Furthermore, in order to maximize the load carried by piezoelectric elements, it is recommended to use soft material around the perimeter of the module.