Modeling and analysis of piezoelectric beam with periodically variable cross-sections for vibration energy harvesting

A bimorph piezoelectric beam with periodically variable cross-sections is used for the vibration energy harvesting. The effects of two geometrical parameters on the first band gap of this periodic beam are investigated by the generalized differential quadrature rule （GDQR） method. The GDQR method is also used to calculate the forced vibration response of the beam and voltage of each piezoelectric layer when the beam is subject to a sinusoidal base excitation. Results obtained from the analytical method are compared with those obtained from the finite element simulation with ANSYS, and good agreement is found. The voltage output of this periodic beam over its first band gap is calculated and compared with the voltage output of the uniform piezoelectric beam. It is concluded that this periodic beam has three advantages over the uniform piezoelectric beam, i.e., generating more voltage outputs over a wide frequency range, absorbing vibration, and being less weight.

梯形变截面悬臂梁式微质量传感器设计与分析

针对微小集中质量测量问题,提出并制备了一种梯形变截面悬臂梁式微质量传感器,建立了梯形变截面悬臂梁式微质量传感器的振动分析模型。采用有限元方法求解其振动控制方程,获得了微质量传感器的灵敏度。仿真分析结果表明,相对于等截面矩形悬臂梁式微质量传感器,单层压电和双层压电结构的变截面悬臂梁传感器的灵敏度分别提高了127.00%和263.00%。采用线切割工艺,加工制备了单压电层梯形变截面结构的微质量传感器并对传感器进行了实验测试,在误差允许范围内,仿真结果与实验结果基本一致,验证了采用梯形变截面悬臂梁式结构可以有效的提高传感器的灵敏度。