MFC压电悬臂梁发电性能研究

Research on the Power Generation Performance of the Piezoelectric Cantilever Using MFC

压电悬臂梁的机电耦合系数正比于压电片起点和终点处的振型斜率差,基于此理论,提出了一种简单而有效的改善MFC压电悬臂梁发电能力的方法。该方法在不改变压电悬臂梁整体质量的前提下,通过改变悬臂梁非发电部位结构以提高其局部刚度,从而增大了压电片起点与终点处的振型斜率差,最终使得悬臂梁的机电耦合系数得到放大。文中分析了改进结构的振型,将之与传统结构进行了对比,并通过实验测试了两种结构的发电能力。实验结果验证了上述理论的正确性,表明改进后的结构可以大幅度提高振动能量收集器的发电能力。

Based on the fact that the electromechanical coupling is proportional to the difference of the mode shape slopes at the starting and ending locations of the piezoelectric beam,an easy but quit effective technique is proposed to improve the power generation performance of the beam significantly. By this method,without changing the entire mass of the beam,the local stiffness of the non-power generation part of the beam is enhanced through structural modification. In this way,the difference of the mode shape slopes mentioned above can be increased, which leads to the magnification of the electromechanical coupling coefficient. The mode shape comparison between two configurations,viz. the modified model and the conventional one,is analyzed using Euler-Bernoulli beam theory. The power generation capabilities of two configurations are studied through experiment. The results verify the correctness of the theory and show that the power generation capability of the modified model is much greater than that of the conventional one.