Effect of subgrade on piezoelectric energy harvesting under traffic loads

Piezoelectric energy harvesting in roads generated by traffic loads was theoretically and experimentally investigated, and an indoor model of a layered road for piezoelectric transformation was developed using the traffic load model groove. Elastic double-layer beams resting on the subgrade soil were used to consider piezoelectric energy harvesting under traffic loads. Based on the vibration differential equations of elastic double-layer beams, the electromechanical equation was obtained using the Fourier transform. The experimental results of the piezoelectric energy harvesting were close to the theoretical ones, which indicated that the proposed method was useful in predicting piezoelectric energy harvesting from roads under traffic loads. The results also show that the influence of the transducer position on the output voltage and power should be considered, and that the thickness of the concrete panel and the condition of the subgrade soil can affect the output voltage and output power of the piezoelectric transducer. Moreover, the electrical energy was proportional to the vibration frequency and the excitation load.