Numerical Analysis of Signal Response Characteristic of Piezoelectric Energy Harvesters Embedded in Pavement

Abstract

Piezoelectric pavement energy harvesting is a technological approach to transform mechanical energy into electrical energy. When a piezoelectric energy harvester (PEH) is embedded in asphalt pavements or concrete pavements, it is subjected to traffic loads and generates electricity. The wander of the tire load and the positioning of the PEH affect the power generation; however, they were seldom comprehensively investigated until now. In this paper, a numerical study on the influence of embedding depth of the PEH and the horizontal distance between a tire load and the PEH on piezoelectric power generation is presented. The result shows that the relative position between the PEH and the load influences the voltage magnitude, and different modes of stress state change voltage polarity. Two mathematic correlations between the embedding depth, the horizontal distance, and the generated voltage were fitted based on the computational results. This study can be used to estimate the power generation efficiency, and thus offer basic information for further development to improve the practical design of PEHs in an asphalt pavement.

Finite Element Modeling and Performance Evaluation of Piezoelectric Energy Harvesters with Various Piezoelectric Unit Distributions

“…In the above equations, the superscripts E and ε above a particular property indicate that the property is defined at zero electrical gradient and at zero strain, respectively. For the piezoelectric effects, two working modes are defined for the piezoelectric materials, which, respectively, are 3-1 mode and 3-3 mode [ 26 ], as shown in Figure 2 .…”

“…The structure of the PEH used in this study is based on the authors’ previous researches [ 23 , 24 , 26 ]. The PEH was designed as a box and was buried in asphalt pavements, which is shown in Figure 3 a.…”

“…effects, two working modes are defined for the piezoelectric materials, which, respec tively, are 3-1 mode and 3-3 mode [26], as shown in Figure 2. The 3-1 mode refers to that the stress components are perpendicular to the polariza tion direction of the piezoelectric materials.…”

“…To maximally utilize the space, the distributions of the piezoelectric units were designed in matrixes by 3 × 3, 3 × 4 and 4 × 4, respectively. According to previous researches [23,24,26], the cross section area of the piezoelectric units is related to the electrical potential; therefore, the total cross section area of the piezoelectric units was controlled in this study. For the distribution of 3 × 3 with diameter of 2 cm, 3 × 4 with diameter of 1.73 cm and 4 × 4 with diameter of 1.5 cm, the total cross section area of the units was 28.27 cm 2 .…”

“…As an initial research, the FE models of the cymbals in their study were simplified to some extent, which were not directly applied in realistic pavements. Yang et al [ 26 ] evaluated the efficiencies of PEHs in different locations in asphalt pavement based on the FE simulation, the results can be used to guide the future PEHs applications in pavement engineering. However, the PEH in Yang’s simulation was simplified as a homogeneous structure, and the details about the internal structure of the PEH were ignored.…”