This paper develops a twist beam for multi-directional energy harvesting using piezoelectric transduction. The working principle of the multi-directional ability is explained by the theory of a pre-twisted beam. A simulation study is performed for concept verification and revealing the potential advantages of the proposed twist-beam vibration energy harvester (VEH). A physical prototype is fabricated and an experimental study is conducted to evaluate the actual performance of the proposed twist-beam VEH for validation. The results show that for the excitation comes from any direction in the plane in parallel with the beam cross-section, the proposed twist-beam VEH can produce a substantial amount of power. The optimal resistance is independent of the excitation direction. Moreover, it is found that the relationships between the output voltage amplitude and the excitation direction are different for the cases around the first and second resonances of the twist-beam VEH. The underlying physics behind this phenomenon is that the dominant motion of the two resonant modes are contrarily different. In addition, the experimental study shows that the first two natural frequencies of the prototyped twist-beam VEH are 22.37 Hz and 41.47 Hz, respectively, which are much closer to each other as compared with those of a conventional plain beam. This feature benefits multi-modal energy harvesting within a targeted frequency range. The prospects regarding further optimization of the proposed twist-beam VEH are discussed.

中文翻译：

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一种用于多方向能量收集的扭曲压电梁

本文开发了一种使用压电换能器进行多方向能量收集的扭曲梁。多向能力的工作原理由预扭梁理论解释。进行了模拟研究以验证概念并揭示所提出的扭梁振动能量收集器 (VEH) 的潜在优势。制造了一个物理原型，并进行了一项实验研究，以评估所提出的扭曲梁 VEH 的实际性能以进行验证。结果表明，对于来自与梁横截面平行的平面中的任何方向的激励，所提出的扭曲梁 VEH 可以产生大量的功率。最佳电阻与激励方向无关。而且，发现在扭梁VEH的第一次和第二次谐振附近的情况下，输出电压幅度与激励方向之间的关系是不同的。这种现象背后的基本物理原理是两种谐振模式的主要运动相反。此外，实验研究表明，原型扭转梁 VEH 的前两个固有频率分别为 22.37 Hz 和 41.47 Hz，与传统平面梁相比，它们彼此更接近。此功能有利于目标频率范围内的多模式能量收集。讨论了进一步优化所提出的扭曲梁 VEH 的前景。