浅球壳型非线性振动能量收集技术：随机理论与动态试验

Miniaturization of electronic components induces the prominent reduction of power consumption, and so triggers the boom of vibration energy harvesting techniques. Nonlinear energy harvesting techniques, especially the bistable modes, have remarkable advantages on the effective bandwidth and output power. This project designs, characterizes, optimizes and verifies the shallow spherical shell-type nonlinear energy harvesting technique through stochastic analysis and dynamical experiment. The stochastically dynamical snap-through mechanism of electro- mechanical coupling shallow spherical shell is investigated to determine the probabilistic properties of snap-through frequency and output power. The performance index is proposed through the compromise of environmental excitation, mean power and the power intensity in time domain, and then geometric parameters and electrode location are optimized. The performance and the optimality of optimal parameters are validated through dynamical experiment. It's the original thought to realize bistable energy harvesting through shallow spherical shell, and this technique has many advantages, such as large effective bandwidth, high output power and adaptation to miniaturization. This research develops the vibration energy harvesting technique which suitable to miniaturization and pave the way for its commercial process, and at the same time, enriches the stochastic dynamics theory of intelligent continuous systems.

电子元器件微型化导致其功耗大幅降低，从而激发了振动能量收集技术的迅猛发展。非线性能量收集技术，特别是双稳技术，在有效频宽和输出功率两方面都具有优势。本项目以浅球壳型非线性随机振动能量收集技术为研究对象，设计、表征、优化并试验验证之。该技术在理论上归结为机电耦合浅球壳的随机动态跳变机制，给出动态跳变频率和输出功率的概率特性；权衡外界振动环境的变化、平均功率及输出功率的时间分布密集度给出性能指标，在此基础上得出最优的浅壳尺寸和电极设计；通过动态试验验证其性能及优化参数的最优性。本项目首次将具本质双稳特性的浅球壳结构应用于振动能量收集，其优点在于：大的有效带宽，高的输出功率以及对微型化的适应性。研究成果发展了适宜微型化的宽带振动能量收集器件，为其工业化的实现奠定基础；并且丰富了智能连续结构的随机动力学理论。

振动能量收集技术越来越受到科学界及产业界的广泛关注，其中压电式振动能量收集器件是最广泛被采用的一种能量转化器件。而其中的非线性振动能量收集技术，特别是双稳技术，在能量收集方面具有显著优势。本项目以双稳非线性振动能量收集器件为研究对象，设计、优化并试验证实具有大的有效带宽和高的输出功率的随机振动收集技术。在理论上，建立了单稳和双稳振动能量收集器件随机响应的分析方法，发展了连续系统随机振动能量收集理论，并以性能指标最大为目标，对振动能量收集器件完成了优化；在实验上，针对双杆型振动能量收集器和柱壳型振动能量收集器，完成了结构优化并进行了实验验证。本项目的研究丰富了随机动力学理论，拓展了随机振动能量收集技术的后续研究方向,研究成果可应用于微型化宽带振动能量收集器件。