挠电智能结构的振动控制与能量采集研究

发布时间：2019-05-27 23:38

【摘要】：智能结构具有体积小、响应快、变形大等特点,可实现结构的传感、振动控制、噪声控制与稳定性控制等,在航空航天、机械电子、生物医学等领域具有重要的应用。挠电材料不需要进行极化处理,不存在退极化和老化问题等,应用方便,因此挠电智能结构在工程应用中具有广泛的应用前景。本文基于一般双曲率厚壳结构建立了包含挠电效应的力电耦合动力学模型,该模型考虑了剪切效应及旋转惯性项,并且考虑了大变形的几何非线性的影响。推导了逆挠电效应作用下的力电耦合动力学方程,并给出了一般双曲率厚壳结构的模态控制响应。基于一般双曲率厚壳结构的动力学方程与挠电振动控制模态响应可简化应用到一般双曲率壳薄壳结构与小变形结构,并且根据特定结构的拉梅常数和曲率半径,可简化应用到不同的壳和非壳结构。本文具体讨论将一般双曲率挠电薄壳应用到挠电矩形板、挠电圆柱薄壳与挠电半球薄壳的简化应用步骤。基于挠电效应推导的挠电控制动力学方程,利用逆挠电效应进行振动控制的关键是构造非均匀的电场即构造电场梯度。本文分别构造了原子力显微镜(AFM)探针激励、导线激励与含金属芯的挠电纤维等产生电场梯度的方式,并对不同的结构进行了振动控制的研究。本文首先建立了基于AFM探针激励的挠电悬臂梁结构的振动控制模型,并给出了激励电压作用下挠电效应引起的悬臂梁的末端位移。同时进行了挠电作动实验,挠电作动器位于不同位置时分别测量了挠电悬臂梁的末端位移,并与理论预测进行了对比,验证了挠电作动理论的可行性。挠电激励引起的作动位移与探针的半径、位置以及挠电梁的厚度等有关,本文优化了不同的参数提高振动控制的效率。基于导线激励构造了产生电场梯度的另外一种方法,并对两边简支两边自由的矩形板进行了振动控制。针对矩形板的不同模态,分别讨论了挠电效应引起的振动控制的位移,并讨论了不同的参数对矩形板振动控制位移的影响,优化振动控制的效果。此外,利用含金属芯挠电纤维引起的电场梯度,对弹性悬臂梁结构进行了振动控制分析。同样对挠电纤维半径、金属芯半径、挠电纤维个数与位置等参数对振动控制的影响进行了分析讨论。此外,本文基于正挠电效应建立了基于一般双曲率壳结构的挠电俘能器模型,推导出了外部激励作用下挠电俘能器在外部负载电阻两端产生的电压与功率输出。根据特定结构的拉梅常数与曲率半径,将一般双曲率壳的挠电俘能器简化应用到挠电圆柱壳俘能器、挠电圆环壳俘能器与挠电悬臂梁俘能器,给出了特定结构俘能器的负载两端的电压和功率输出表达,并对圆环壳俘能器进行了具体的参数分析优化输出功率。为了讨论挠电效应在工程上的应用,本文针对圆环面壳结构进行了挠电分布式传感与振动控制分析,针对圆环壳不同的模态,分析了不同的弯曲角度与不同的应变分量对挠电传感与振动控制的影响。
[Abstract]:The intelligent structure has the characteristics of small volume, fast response, large deformation and the like, and can realize the sensing, vibration control, noise control and stability control of the structure, and has important application in the fields of aerospace, mechanical electronics, biomedicine and the like. The flexible electric material does not need to be polarized, does not have the problem of depolarization and aging, and the like, and is convenient to apply; therefore, the flexible electric intelligent structure has a wide application prospect in the engineering application. In this paper, based on the general double-curvature thick-shell structure, a force-electric coupling dynamic model with a flexible electric effect is established, which takes into account the shearing effect and the rotational inertia term, and takes into account the influence of the geometrical non-linearity of the large deformation. In this paper, the dynamic equations of the force-electric coupling under the action of the reverse-bending electric effect are derived, and the modal control response of the general double-curvature thick-shell structure is given. The dynamic equation and the flexural vibration control mode response based on the general double-curvature thick-shell structure can simplify the application to the general double-curvature shell shell structure and the small deformation structure, and can simplify the application to different shell and non-shell structures according to the pull-in constant and the radius of curvature of the specific structure. In this paper, the general double-curvature flexible thin shell is applied to the simplified application of flexible electric rectangular plate, flexible electric cylindrical shell and flexible electric hemisphere thin shell. Based on the dynamic equation of flexible electric control, the key to the vibration control is to construct the non-uniform electric field, that is, to construct the electric field gradient. In this paper, an atomic force microscope (AFM) probe excitation, a wire excitation and a flexible electric fiber containing a metal core are respectively constructed to generate electric field gradient, and the vibration control of different structures is studied. In this paper, the vibration control model of the cantilever beam structure excited by the AFM probe is firstly established, and the end displacement of the cantilever beam caused by the flexible electric effect under the action of the excitation voltage is given. At the same time, the flexible electro-operation experiment is carried out, the end displacement of the flexible electric cantilever beam is measured respectively when the flexible electric actuator is in different positions, and the theoretical prediction is compared, and the feasibility of the flexible electric actuation theory is verified. The action displacement caused by flexible electric excitation is related to the radius and position of the probe and the thickness of the flexible beam, and the efficiency of the vibration control is improved by the different parameters. In this paper, an alternative method for generating electric field gradient is constructed based on the wire excitation, and the vibration control is carried out on the rectangular plates which are simply supported on both sides. In the light of the different modes of the rectangular plate, the displacement of the vibration control caused by the flexible electric effect is discussed, and the influence of different parameters on the vibration control displacement of the rectangular plate is discussed, and the effect of the vibration control is optimized. In addition, the vibration control analysis of the elastic cantilever structure is carried out by using the electric field gradient caused by the metal-core flexible electric fiber. The influence of the parameters such as the radius of the flexible electric fiber, the radius of the metal core, the number and the position of the flexible electric fiber on the vibration control is also discussed. In addition, based on the positive-flex electric effect, the model of the flexible electric energy capture device based on the general double-curvature shell structure is established, and the voltage and the power output of the external load resistor at the two ends of the external load resistor are derived. according to the tension and the radius of curvature of the specific structure, the flexible electric energy capture device of the general double-curvature shell is simplified to be applied to a flexible electric cylindrical shell capture device, a flexible electric circular ring shell capture device and a flexible electric cantilever beam energy collector, and the voltage and the power output expression at the two ends of the load of the specific structural energy collector are given, And the specific parameter analysis of the ring shell capture device is carried out to optimize the output power. In order to discuss the application of flexible electric effect in engineering, this paper analyzes the structure of ring shell, and analyzes the effects of different bending angles and different strain components on the sense of flex-wire and vibration control for the different modes of the ring shell.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TM619

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