非线性双稳压电梁随机动力响应分析与振动能量获取研究

Energy sources are the essential necessity for human life. Besides the traditional energy sources, other developed and utilized resources are an important approach to meet the needs of energy. Ambient vibration is ubiquitous, and the energy harvesting from the ambient vibration is a key self-solution to power a minitype electronic device. The proposal is based on the previous theoretic and technical research of bistable dynamics and its characteristic extraction, in order to extend to study the method and technology of vibrational energy harvesting of bistable system. The project takes the nonlinear bistable piezoelectronic cantilever beam as the study object, and the bistable structure with the elastic supporting outside magnet is proposed. In this proposal, under the condition of different vibration strength and different spectral distribution, the mechanism of the response of the bistable piezoelectronic beam and its energy harvesting is going to be investigated. The relationship among the nonlinear characteristic of the bistable piezoelectronic beam and the vibration response as well as energy converter will be exposed, too. The influence of the nonlinear force on the beam dynamical response and its energy acquisition is also to be analyzed. In addition, the diversity of the beam dynamics and its energy capture under periodic vibration plus stochastic oscillation will be explored in the project. The goal of the proposal is to realize the optimal approach of vibrational energy harvesting for the designed bistable piezoelectronic beam, to overcome the limitation of the linear energy capture and to demonstrate the advantage of nonlinear energy harvesting.

能源是人类生存的根本要素，开发利用除了传统能源外的其它形式能源是解决能源需求的重要手段。环境振动普遍存在，环境振动能量的获取采集是为小型电子设备提供电力的一种重要的自主解决方案。课题在前期双稳动力学特性及其特征提取理论和技术的研究基础上，进一步扩展研究基于双稳动力系统的振动能量获取方法与技术。课题首先以非线性双稳压电悬臂梁系统为研究对象，提出弹性支撑外部磁铁的双稳动力结构，研究大小强度不同的振动激励及其不同谱分布特征对双稳压电梁的响应和能量获取的影响机制，揭示双稳压电梁结构的非线性特征量与梁的振动响应及能量转换的关系与规律，分析非线性力与双稳压电梁的动态响应及能量获取的关联机理，探索包含周期成分的随机激励条件下双稳压电梁的动力学行为与双稳能量获取差异，实现非线性双稳压电梁随机动力响应的优化能量获取技术，克服线性能量获取的局限性，阐明非线性能量获取方法的优越性。

针对刚性支撑双稳压电梁能量采集系统在低强度振动环境下，存在单稳小幅振荡导致系统机电能量转换效率降低的缺陷，课题提出了弹性支撑双稳压电梁能量采集系统构想，揭示了低强度随机激励下弹性支撑双稳压电梁振动响应与能量获取的机理，阐述了高斯宽带噪声和粉红噪声随机激励谱特征对弹性支撑双稳压电梁的振动响应与能量转换的影响机制，掌握了不同磁铁间距、不同磁铁密度、不同梁尺寸刚度等结构参数影响系统响应的规律和采集能量的本质特性，获得了系统在周期和随机信号共同激励环境下能量转换的原理和技术特征，为优化设计弹性支撑能量采集系统结构奠定了理论和技术基础。实际工况实验检验了弹性支撑双稳压电梁系统能量获取的有效性，在低强度激励下，所研究设计出的弹性支撑系统的输出功率超过目前常规刚性支撑系统输出功率的2倍以上，特别是对于实际工况激励环境，弹性支撑双稳压电梁能量采集系统无需实时调整结构参数，就能够很好地适应强度变化的随机激励，实现高效的机电能量转换。.课题相关扩展的创新研究结果有：改进了磁化电流法磁力分析模型，提高了双稳压电梁能量采集系统的磁力计算精度；提出了脉冲序列整体平移的单稳脉冲信号检测方法，克服了参数调节实现随机共振的困难；给出了二维Duffing振子的广义调参随机共振方法；提出了基于频域信息交换的随机共振方法，克服了高采样频比制约变尺度随机共振检测信号的缺陷。