基于直角复合悬臂梁的压电振动能量回收研究

发布时间：2018-05-19 18:26

本文选题：能量回收 + 压电效应　；参考：《安徽大学》2017年硕士论文

【摘要】：随着低功耗无线电子设备的迅猛发展,如何为这些微型电子设备供能也得到了研究人员的广泛关注。目前,无线电子设备多利用电池供电,但传统的化学电池存在使用寿命有限,某些场合还存在更换难度较大的弊端。寻求新型供能方式已成为当务之急。振动机械能普遍存在于周围环境中,若能得到较好的回收利用就可将其作为一种潜在的能量替代方式,实现电子设备的自我供能,那么就可以一劳永逸地解决微电子设备对外部电源的依赖问题。本文首先论述生活中比较常见且能够回收利用的各种能量源及能量回收的方式。其次介绍了压电振动能量回收和近年来国内外的研究成果与现状,分析总结了各种优化方式及其可借鉴之处。这些方式中,基于压电效应的振动能量回收以其能量密度高、结构简单、无电磁污染、易于微型化等优点,有着十分光明的应用前景。接下来从压电材料出发,结合压电材料的本构方程和振动模式的基本理论,分析了压电振动能量回收过程的机电转换机理,得出了理论上悬臂梁结构输出功率表达式并简要讨论了影响其输出功率的因素。基于以上分析,我们对所提出的直角复合悬臂梁进行了建模仿真与结构优化。利用有限元的方法,结合ANSYS软件对其进行了模态仿真,提取了前四阶振动模态结果和应变分布情况。在此基础之上,得到了结构的一阶固有频率为23.121Hz、三阶固有频率为67.898Hz。此外还进行了结构的谐响应分析,在1～100Hz激励频率范围内,每隔1Hz进行扫频,载荷选择正弦振动激励,并且忽略振型阻尼,按照固有频率收敛显示结构中直梁根部压电陶瓷片上应变的频率响应。随后讨论了在结构设计过程中,所加载的质量块大小、结构副梁长度、副梁厚度等因素对直角复合悬臂梁谐振频率的影响,以此来指导实验测试中直角复合悬臂梁的实物制作。随后结合上述研究基础,详细阐述了直角复合悬臂梁的制作流程,测试了它的电压频率响应和功率输出表现,并将其与传统的悬臂梁进行对比测试,验证了仿真分析的有效性。结果表明,在最大加速度为0.08g的正弦振动激励下,其最大输出功率可以达到3.4mW,而对比的传统悬臂梁为2.2mW,即本文提出的直角复合悬臂梁的发电性能要优于同样激励条件下的对比传统悬臂梁。综上所述,本文的研究有利于减小压电振动能量回收装置的体积并提高系统的转换效率,对微型传感器等电子设备实现自主供能具有重要意义。
[Abstract]:With the rapid development of low power wireless electronic devices, researchers pay more attention to how to power these micro electronic devices. At present, the wireless electronic equipment mostly uses the battery to supply power, but the traditional chemical battery has the limited service life, some occasions also has the shortcoming which the replacement is difficult. It is urgent to seek new energy supply methods. Vibration mechanical energy generally exists in the surrounding environment. If it can be recycled, it can be used as a potential energy substitute to realize the self-supply of energy for electronic equipment. Then the dependence of microelectronic devices on external power can be solved once and for all. This paper first discusses the various energy sources and ways of energy recovery, which are common in life and can be recycled. Secondly, the paper introduces the energy recovery of piezoelectric vibration and the research results and present situation at home and abroad in recent years, and analyzes and summarizes all kinds of optimization methods and their references. Among these methods, vibratory energy recovery based on piezoelectric effect has a bright future because of its advantages of high energy density, simple structure, no electromagnetic pollution and easy miniaturization. Then, starting from piezoelectric material, combining the constitutive equation of piezoelectric material and the basic theory of vibration mode, the mechanism of electromechanical conversion of piezoelectric vibration energy recovery process is analyzed. The expression of the output power of cantilever beam structure is obtained theoretically and the factors influencing the output power are discussed briefly. Based on the above analysis, we model and simulate the right angle composite cantilever beam and optimize its structure. The modal simulation is carried out by using finite element method and ANSYS software. The first four vibration modal results and strain distribution are extracted. On this basis, the first-order natural frequency of the structure is 23.121 Hz and the third-order natural frequency is 67.898Hz. In addition, the harmonic response of the structure is analyzed. In the range of 1~100Hz excitation frequency, every frequency sweep is carried out at 1Hz intervals, the load selects sinusoidal vibration excitation, and the mode damping is ignored. The frequency response of the strain on the piezoelectric ceramic plate at the root of the straight beam is displayed according to the natural frequency convergence. Then, the influence of the size of the mass block, the length of the auxiliary beam and the thickness of the auxiliary beam on the resonant frequency of the right-angle composite cantilever beam is discussed in the course of the structural design, so as to guide the physical fabrication of the right-angle composite cantilever beam in the experiment. Then, based on the above research basis, the fabrication process of the rectangular composite cantilever beam is described in detail, its voltage frequency response and power output performance are tested, and compared with the traditional cantilever beam, the validity of the simulation analysis is verified. The results show that under the sinusoidal vibration excitation with the maximum acceleration of 0.08g, The maximum output power can reach 3.4 MW, while the conventional cantilever beam compared with the conventional cantilever beam is 2.2 MW, that is, the power generation performance of the rectangular composite cantilever beam proposed in this paper is better than that of the conventional cantilever beam under the same excitation conditions. To sum up, the research in this paper is helpful to reduce the volume of piezoelectric vibration energy recovery device and improve the conversion efficiency of the system. It is of great significance to realize the independent energy supply for electronic devices such as micro sensors.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM619;TN384

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