Piezoelectric energy harvesting from roadway
Creators: name: Jasim, Abbas Fadhil
Publisher: name: No Publisher Supplied
Year: 2018

description: Energy harvesting technologies have attracted much attention as an alternative power source of roadway accessories in different scales. Piezoelectric materials, which have been widely used in sensor technologies due to their cost-effectiveness, are capable of producing electrical energy from mechanical energy. Therefore, piezoelectric transducers can be designed to harvest the wasted mechanical energy generated under wheel loading that can be stored in an electronic capacitor or integrated with sensors for in-situ road condition monitoring.  This dissertation aims to develop a novel design of a piezoelectric transducer with optimized geometry for energy harvesting under vehicular loading in the roadway. The novel Bridge transducer with layered poling is designed to increase the piezoelectric coefficient and the relative dielectric permittivity, which produces much higher energy than traditional transducers. Finite element analysis (FEA) was conducted to predict the generated energy output and the resulted mechanical stress in the lead zirconate titanate (PZT) transducer. The results of the optimization analysis indicate that the optimized geometry parameters can generate the maximum energy output within the stress failure criteria. Later, an energy harvester module that contains multiple stacked transducers, 64 novel transducers, was fabricated and tested under single pulse and cyclic loading events. The main objectives of this part were to evaluate the energy output and fatigue behavior of the piezoelectric energy harvester using laboratory testing and numerical simulation. The analysis results showed that two different material failure models need to be considered in relation to mechanical failure of the Bridge transducer, namely tensile and shear failure. This emphasizes that the optimum design of energy module should consider the balance of energy output and fatigue life that are affected by the fabrication of a single Bridge transducer and the packaging design of the energy module.  To take into account the nature of the energy harvester-pavement interaction and to achieve better computation efficiency, the effect of this interaction on pavement responses was studied using a decoupled approach. First, a 3D pavement model was built, and then the pavement responses under the tire contact stresses were calculated. The effects of energy harvester-pavement interaction at different locations, horizontally and vertically, were also analyzed. The results show that the maximum power output of the energy harvester module is around 122mW at a vehicle speed of 65mph and 3 inches embedded depth. Furthermore, embedding the energy harvesting module below 3 inches from the pavement surface is the best location to maximize both power output and service life.   Finally, to reveal the potentials of some important technologies for harvesting energy from a pavement network, a case study is discussed, which uses the New Jersey roadway network as the example for analysis. The potential of electrical energy generation for thermoelectric and piezoelectric (cymbal and novel bridge design) technologies were considered. Based on available energy harvesting technologies, a thermoelectric-based pipe system covering the entire New Jersey roadway network may potentially collect 20.11 GWh electrical energy per day, while a piezoelectric transducer system may collect around 3.74 and 10.01MWh of electrical energy per day for cymbal and novel bridge transducer designs, respectively.