تحلیل اجزای محدود برداشت کننده انرژی پیزوالکتریک توسط سلول آگزتیک با هندسه جدید

In this study, a numerical analysis using the finite element method is performed and developed for a novel geometry of a piezoelectric energy harvester with a negative Poisson’s ratio, inspired by the auxetic structure, to enhance strain energy and consequently improve output power efficiency. The structure consists of a steel beam and an auxetic cell made of the same material with a newly designed geometry, positioned at one end of the beam, with a piezoelectric element attached to the auxetic cell. The energy harvesting system is subjected to base excitation with an acceleration equal to gravitational acceleration. The results show that the proposed new geometry, while maintaining the same overall cell dimensions as the re-entrant auxetic structure, achieves a 394% increase in harvested voltage, and the harvested power is enhanced by a factor of 14.77 compared to the conventional auxetic design. According to the results, for the re-entrant auxetic geometry, the maximum voltage is 0.295 V at a frequency of 265 Hz, whereas for the new auxetic geometry, the maximum harvested voltage reaches 1.134 V at a frequency of 119 Hz.