基于能量法的双晶压电悬臂梁发电装置机电耦合系数分析

针对双晶压电悬臂梁发电装置机电两类能量通过压电效应耦合强弱的问题,将能量法应用到双晶压电悬臂梁发电装置机电耦合系数的分析中。开展了双晶压电悬臂梁发电装置机电耦合系数的理论分析,并建立了其与双晶压电悬臂梁发电装置尺寸参数和材料特性之间的关系,对双晶压电悬臂梁发电装置机电耦合系数与其尺寸参数和材料特性的关系模型进行了实验验证和数值模拟。研究结果表明,实验值与理论解有较好的一致性,且都在压电片厚度为0.25 mm时开路电压最大,验证了该理论模型的可靠性。此外,随着压电梁厚度比的不断增大,其机电耦合系数单调递增;同时,较大的弹性模量比有利于压电梁机电耦合系数的提高,且相对于钢弹性基片,铍青铜弹性基片更有利于压电梁机电耦合系数的提高。

Analysis of electromechanical coupling coefficient for piezoelectric bimorph cantilever based on energy method

In order to solve the problems of the piezoelectric effect of the piezoelectric bimorph cantilever, the energy method was investigated. After the analysis of the electromechanical coupling coefficient for piezoelectric bimorph cantilever, the theory model of the electromechanical coupling coefficient for piezoelectric bimorph cantilever was established. The theory model was validated by experiments and the relations between the electromechanical coupling coefficient for piezoelectric bimorph cantilever and structural parameters and material characteristics were simulated. The results indicate that the optimal thickness of the piezoelectric bimorph cantilever is 0.25 mm obtained by theory analysis, which is consistent with the experimental results. Moreover, with the increasing of thickness ratio, the electromechanieal coupling coefficient increases. Meanwhile, with the increasing of elastic modulus ratio, the electromechanical coupling coefficient increases and beryllium bronze flexible substrate harvester is superior to the steel flexible substrate harvester.