压电振子的工作频带宽度是影响压电振动能量收集器发电效率的关键指标。该文旨在分析一种锯齿型阵列式压电振动能量收集器结构模态频率, 为压电振子的动力学设计提供参考。首先, 基于弹性梁振动理论, 推导了锯齿型压电梁的动力学方程, 并分析了影响压电梁模态频率的因素。然后, 通过COMSOL建立锯齿形压电梁的有限元模型, 分析了其频响特性、功率与负载阻抗匹配特性及加速度依赖性。最后, 通过实验研究测试了锯齿型压电梁的电压幅频特性曲线, 验证了理论分析与仿真模拟结果的合理性。结果表明, 锯齿型阵列式压电振动能量收集器能够有效地拓宽工作频带, 进而提高发电效率。

The working frequency band width of piezoelectric vibrator is a key index that affects the efficiency of piezoelectric vibratory energy collector. In this paper, the modal frequency of an array piezoelectric vibration energy collector is analyzed, which can be used as a reference for the dynamic design of piezoelectric vibrators. Firstly, based on the vibration theory of the elastic beam, the dynamic equations of the saw-tooth piezoelectric beam are derived, and the factors affecting the modal frequency are analyzed. Then, the finite element model of the saw-tooth piezoelectric beam is established by COMSOL, and its frequency response, power and load impedance matching characteristic and acceleration dependence are analyzed. Finally, the voltage amplitude-frequency characteristic curve of the saw-tooth piezoelectric beam is tested by experimental research, which verifies the rationality of the theoretical analysis and simulation results. The results show that the saw-tooth array piezoelectric vibration energy collector can effectively broaden the working frequency band and improve the power generation efficiency.