Electric energy output model of a piezoelectric transducer for pavement application under vehicle load excitation

Piezoelectric transducers convert mechanical energy in the pavement into electrical energy, providing a new energy supply for road auxiliary facilities. To quantify the relationship between vehicle loads and the electrical energy output of a piezoelectric transducer, the rolling process of a vehicle on the piezoelectric transducer is analyzed. Two output models considering the moving load are established. New piezoelectric transducers are fabricated to verify the models, and differences between the models and the test values are compared in five areas. The loading process was affected by the shape of the piezoelectric transducer and the grounding area of the tire. Although the two models are similar in form, the results show that Model 2 can better represent the electrical energy output because the percentage differences from test results for Model 1 are unstable. Materials with a high strain constant and a low equivalent capacitance can help the transducer achieve higher output voltage and power. Heavy-duty high-speed traffic loads can increase the piezoelectric output of the transducer. The output voltage increases continuously with resistance, whereas the output power has a peak value at a matched resistance. This study can provide a reference for the design of piezoelectric transducers and piezoelectric pavements.