为解决压电振动能量收集结构难以同时满足宽频带、三维、高效采集等要求的问题, 提出一种以Z型梁代替集中质量块的压电振动能量收集结构。通过Z型梁引入非线性质量, 使收集器在低频范围内集中更多模态, 拓宽采集频带。利用Z型梁结构的纵向和横向不稳定性实现收集器的三维度能量采集功能。分析了Z型梁在宽度增加后的动力学特性, 探讨了压电片阵列排布的采集性能, 并建立仿真模型和搭建实验平台, 与螺旋形梁结构和经典悬臂梁质量块结构的动力学特性进行了对比。仿真及实验结果表明: 当梁折叠层数为7层时, 频率在50 Hz以内的模态数量达到了9个, 在1~100 Hz间隔1 Hz的谐波激振下, Z型压电梁正向的采集电压-频率曲线峰值多达4个, 且主要集中在0~40 Hz, 最大开路电压达到16 V, 大大拓宽了采集频带; 横向和纵向的最大开路电压峰值均在10 V以上, 横向和纵向的采集电压-频率曲线峰值数量均大于4个, 实现了三维度能量采集, 负载10 kΩ时最大输出功率达到了0.18 mW; 在Z型梁宽度增加到100 mm时, 在200 Hz范围内模态数大于30个, 双贴片串联采集电压曲线峰值多达4个, 最大电压达到了14 V, 验证了Z型梁适用于压电片阵列排布。

In order to solve the problem that the piezoelectric vibration energy harvesting structure is difficult to meet the acquisition requirements of wide frequency band, 3D and high efficiency at the same time, a piezoelectric vibration energy harvester structure with the concentrated mass replaced by Z-type beam was proposed. Nonlinear mass was introduced by the Z-type beam structure, which enabled more modal of the harvester to be concentrated in the low frequency range, increased the acquisition frequency band, and realized the 3D energy harvesting function of the harvester by the instability of the horizontal and longitudinal Z-type beam structure. The dynamic characteristics of the Z-type beam after increasing the width were analyzed, and the energy acquisition performance of the piezoelectric array was discussed. Models and experimental platforms were built for simulation and experimental verification. Then, the dynamic characteristics of the Z-type piezoelectric beam was compared with those of the spiral beam structure and classic cantilever beam mass structure. The simulation and experimental results show that when the beam has seven folded layers, the number of modes with frequency within 50 Hz can reach nine, and in the 1-100 Hz range and 1 Hz harmonic excitation, the peaks of the forward acquisition voltage-frequency curve reaches up to four and are mainly concentrated in the 0-40 Hz range. The maximum open circuit voltage is up to 16 V, greatly widening the acquisition frequency band. The maximum open circuit voltage peaks in both the horizontal and vertical directions are above 10 V, while the peaks of the horizontal and vertical acquisition voltage-frequency curves are greater than four, achieving 3D energy acquisition. The maximum output power reaches 0.18 mW when the load is 10 kΩ. When the width of the Z-type beam is increased to 100 mm, the number of modes is greater than 30 in the range of 200 Hz. The peak number of acquisition voltage curves of double patch in series is up to four. The maximum voltage reached 14 V, which proves that the Z-beam is suitable for the arrangement of the piezoelectric array.