چكيده به لاتين
Civil infrastructures such as roadways as a favorable source of vibrations, have become one of the major sources of renewable energy. Energy harvesting using piezoelectric materials is an efficient technique among energy scavenging methods employed in asphalt pavements by converting mechanical stress into usable electrical energy. Several designs are reported in the literature; however, what is less discussed is the design procedure. In this work, a design procedure is proposed considering a fixed volume of piezoelectric materials. The objective is to maximize the harvester performance, considering electrical and mechanical aspects, simultaneously. Output power, the level of induced stress on the piezoelectric material, endurance limit and the coupling of the device with the pavement are considered. Furthermore, the electrical degradation of the harvester using PZT-5A material is analyzed. As a case study, a finite element model of a piezoelectric harvester is developed and validated with experimental results. A parametric study is then carried out in order to improve both the electrical and mechanical characteristics of the device. Various parameters, such as piezoelectric disks cross-section, piezoelectric material, and the disks aspect ratio are considered. Six sets of numerical studies are carried out, including three piezoelectric materials (PZT-4, PZT-5A, and PZT-5H) and two prototypes (consisting of three and four disks). A design point is suggested for each set. An overall design point is then suggested which surpasses other points considering the overall performance. A feasibility study is carried out on the possibility of employing the proposed harvester using the average annual daily traffic data for two selected design points to show the effectiveness of the discussions and results made in this work. Finally, the degradation of the selected PZT-5A harvesters after 10 years of cyclic loading are suggested for two loading circumstances. It is suggested that the design procedure introduced in this study provides the designer with enhanced harvesters considering various aspects of the device performance, as well as economic considerations regarding the amount of used piezoelectric material. A feasibility study is carried out on the possibility of employing the proposed harvester using the average annual daily traffic data for two selected piezoelectric harvesters to show the effectiveness of the discussions and results made in this work.
