Cymbal型压电发电装置等效压电常数分析

Analysis of Cymbal piezoelectric generator's effective piezoelectric strain constant

压电发电工作于低频时所收集的能量与其等效压电常数和等效电压常数的乘积成正比。为了研究Cymbal型压电发电装置的等效压电常数,建立了Cymbal型压电发电装置的三维有限元分析模型,并分析得出了等效压电常数计算公式;详细地分析了Cymbal型发电装置中金属帽的材料和厚度、金属腔底端直径和顶端直径、金属腔高度、压电陶瓷片厚度等因素对等效压电常数的影响,并给出了等效压电常数的优化准则。试验结果表明,经优化后可获得的等效压电常数大约相当于压电陶瓷本身的60倍。

The harvesting energy of piezoelectric generator is proportional to the product of effective piezoelectric strain constant and effective piezoelectric voltage constant at low frequency.In order to study the effective piezoelectric strain constant of the cymbal piezoelectric generator,the 3D finite element analysis（FEA） model of the generator was established,and effective piezoelectric strain constant calculation formula was also given.Besides,the influences of the metal cap material type,the metal cap thickness,the metal cavity bottom diameter,the cavity top diameter,metal cavity height and the PZT thickness on the effective piezoelectric strain constant of cymbal piezoelectric generator were analyzed,and some optimization criterions were given.Results indicate that the obtained effective piezoelectric strain constant is about as 60 times as that of PZT itself.