多稳态压电振动能量采集器的非线性动力学特性及其实验研究

Nonlinear dynamic characteristics and experimental validation of a multi-stable piezoelectric vibration energy harvester

为了提高非线性双稳态压电振动能量采集器的输出性能,提出了一种基于磁⁃机⁃压电耦合的非线性多稳态振动能量采集器,通过在双稳态压电振动能量采集器模型基础上增加一对外部磁铁,构造了具有四个稳态的非线性压电振动能量采集器。利用磁偶极子理论建立了采集器悬臂梁末端磁铁与外部磁铁之间的非线性磁力模型;利用Hamilton原理和Raleigh⁃Ritz方法建立了四稳态压电振动能量采集系统的分布参数机电耦合动力学模型;仿真分析了磁铁水平间距和外部磁铁间距等参数对系统非线性磁力、非线性分岔特性和动力学特性的影响。制作了四稳态压电振动能量采集器原理样机,搭建了样机性能测试平台,实验结果与仿真结果具有较好的吻合度。研究结果表明四稳态压电振动能量采集器可以在低激励水平作用下显著提高能量收集效率,且具有较宽的工作频带。

In order to improve the output performances of the bi-stable piezoelectric vibration energy harvester(BPEH),a multistable piezoelectric vibration energy harvester formed by the magneto mechanical piezoelectric coupling effect is proposed.By intro⁃ducing a pair of external magnets into the BPEH,a quad-stable piezoelectric vibration energy harvester(QPEH)is developed.The nonlinear magnetic force and potential energy of the energy harvester is firstly derived based on the magnetic dipole theory,and then the nonlinear dynamic model of the proposed harvester is derived based on the Hamilton principle and the Raleigh-Ritz meth⁃od.Some simulations are performed to reveal the effect mechanisms of the system parameters on the nonlinear magnetic force and the dynamic characteristics of the energy harvester.A prototype of the QPEH is manufactured and the experimental system is set⁃up.The experimental results are well agreeable with the simulation results,which testified the proposed dynamic model is correct.The results show that the QPEH oscillating into a quad-stable motion generates wider bandwidth and higher output performance than those of it oscillating into a bi-stable motion.