一种具有新型动力放大器压电悬臂梁俘能器计算模型和解析解

为了提高压电振动能量俘获的效率,提出了一种新型的压电悬臂梁俘能器。新的压电俘能器在悬臂梁固定端安装一个新型动力放大器系统,另一端带有一个有限尺寸的质量块。新型动力放大器由平移及转动约束的弹簧-质量块系统组成。考虑有限尺寸质量块的质量分布效应和平移及转动约束的弹簧刚度等结构参数的影响,利用广义Hamilton原理,针对带有新型动力放大器的压电式悬臂梁俘能器,建立了分布参数型运动微分方程,获得了相应的特征函数,分析了自振频率和能量俘获效果。分析结果表明,考虑质量块偏心距和转动惯量可提高能量俘获效率的预测精度;合理选择动力放大器的平移及转动弹簧刚度可提高能量俘获的效率,降低俘能器的共振频率。

Modeling and analytical solution of piezoelectric cantilevered energy harvester with a new dynamic magnifier

In order to improve the efficiency of piezoelectric vibration energy harvesting,a cantilevered piezoelectric vibration energy harvester is proposed.The new cantilevered piezoelectric energy harvester consists of a new dynamic magnifier (a translation-and rotation-restrained spring-mass system) installed at the restrained end and a tip mass at the free end.Taking into account the translation and rotation-restrained stiffness,and the distribution effect of the tip mass over a finite length,a distributed parameter model of piezoelectric cantilevered energy harvesters is developed by using the generalized Hamilton''s principle.The eigen-function and natural frequency formulation of the presented model are obtained.The efficiency of energy harvesting is investigated.The analytical results show that the accuracy of predicting energy harvesting efficiency can be improved by considering the eccentricity of mass and moment of inertia.A reasonable selection of the translational and rotational spring stiffness can improve energy harvesting efficiency,and reduce the resonant frequency of the energy harvesting system.