查询词典 piezoelectric

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

The three control systems respectively were as follows:(1) The measuring part of the first one was displacement piezoelectric sensor. A pair of piezoelectric sensor/actuator was collocated by each side of the first solar array plate. The compensator was H = 2395-s;(2) The measuring part of the second one was also displacement piezoelectric sensor.A pair of piezoelectric sensor/actuator was collocated by each side of the whole solarfan.Tthe compensator was H = 244s;(3) The measuring part of the third one was velocity piezoelectric sensor.A pair of piezoelectric sensor/actuator was collocated by each side of the three solars array plates near to the body of satellite.

三种控制系统分别是：(1)、采用压电位移传感器，压电传感器／驱动器对同位布置于内板的边缘，控制器补偿函数为H=2395s~(1／2)；(2)采用压电位移传感器，压电传感器／驱动器对同位布置于整个太阳帆板的边缘，这是一种理想的情况，控制器补偿函数为H=244s~(1／2)；(3)采用压电速率传感器，压电传感器／驱动器对同位布置于靠近星体的三块基板边缘，控制器补偿函数为H=2370s~(1／2)。

The piezoelectric motor includes a piezoelectric member which generates a first vibration mode and a second vibration mode simultaneously by an applied power and a frictional member of which a portion is insertedly attached into a concave portion indentedly formed on one side of the piezoelectric member, wherein the frictional member is in an elliptic motion by the vibration generated by the piezoelectric member, so that an influence of the attachment of the frictional member to a resonance frequency can be minimized.

该压电电机包括：压电构件，通过施加的功率同时产生第一振动模式和第二振动模式；摩擦构件，摩擦构件的一部分插入地附着到凹入地形成在压电构件的一侧上的凹入部分中，其中，摩擦构件通过由压电构件产生的振动进行椭圆运动，从而能够使附着摩擦构件对谐振频率的影响最小化。

An idea for analyzing aproblem of piezoelectric dynamics,that treats the excitation of the electricfield in a piezoelectric media as an external exciting action acting on thepiezoelectric media and simultaneously regards the piezoelectric media as anormal elastic media,is given based on the analysis of the electromechanicalcoupling relationships in the piezoelectric media under dynamic condition.

在分析动态情形下压电介质中机电耦合关系的基础上，提出将压电介质中电场的激励作用处理为作用于压电介质的外界激励作用，同时将压电介质视为普通弹性介质的分析压电动力学问题的思路。

A series of experiments were done to substantiate the feasibility of the different piezoelectric cochlea implants in vitro and in vivo . The unpoled ceramic had no piezoelectric characteristic and no ability to decrease the threshold, while the poled ceramic had obvious piezoelectric effect to recover the hearing. Based on these results, it can be affirmed that the piezoelectric cochlea implant can activate the nerve and decrease the threshold.

本研究通过未极化与极化的高灵敏性压电陶瓷的对比，从体外模拟实验中的声电响应曲线和动物体内植入实验的结果中得到：未极化的压电陶瓷没有压电响应，而极化后的压电陶瓷能够将声音信号转化为电信号，证实了压电陶瓷的压电特性的确可以刺激动物的听神经，从而降低听阈阈值。

In chapter three, the passive vibration control of a smart cantilever beam with piezoelectric shunt damping system is studied theoretically. In this chapter, the mechanical impedance of piezoelectric shunt damping system is analyzed, and the parameters of the RLC piezoelectric shunt circuit are optimized via transfer function of the piezoelectric shunt damped beam in order to optimize the vibration damping effect.

第三章。研究了利用压电分流阻尼系统进行压电智能悬臂梁被动振动控制的方法，分析了压电分流阻尼系统的机械阻抗，并通过传递函数方法对RLC串联压电分流谐振电路元件的参数进行了优化，以使压电分流阻尼系统的阻尼效果达到最优。

Chapter three and four analyze two kinds of piezoelectric transformers based on the three-dimensional piezoelectric linear theory and methods of thickness-shear mode circular cylinder piezoelectric transformer and torsional mode cylindrical thin shell piezoelectric transformer.

第三章和第四章以线性压电理论为基础，结合分离变量法和弹性力学的方法，具体分析了两类压电变压器，得到了各自问题的解析解。

In this thesis three kinds of piezoelectric transformers are investigated, including circular cylinder piezoelectric transformer of thickness-shear mode, cylindrical thin shell piezoelectric transformer of torsional mode and multi-layered rectangular plate piezoelectric transformer of thickness-twist mode.

本文研究了三种不同结构模态的压电变压器，包括基于厚度剪切模态的圆筒结构压电变压器、基于扭转模态的壳结构压电变压器和基于厚度扭转模态的多层矩形板结构压电变压器。

With aid of techniques of analytical continuation and conformal mapping, exact solutions are obtained for three typical problems concerning Eshelby's inclusion. The three problems are1 interaction between an arbitrarily shaped Eshelby inclusion and a circular inhomogeneity in transversely isotropic piezoelectric medium; 2 interaction between an arbitraily shaped Eshelby inclusion and an interface in anisotropic piezoelectric medium, the interface in our investigation may be a perfect interface, or a frictionless slipping interface , or a compliant electrode layer is embedded along the full interface of the bimaterials; 3 interaction between an arbitraily shaped Eshelby inclusion and an elliptical hole in anisotropic piezoelectric medium.

通过采用解析延拓和共形映射技术，获得了压电复合材料中有关Eshelby夹杂三个典型问题的精确弹性解答，即横观各向同性压电介质中任意形状的Eshelby夹杂与圆柱异相夹杂间相互作用；一般各向异性压电介质中任意形状的Eshelby夹杂与双压电材料所形成界面的相互作用，我们所考虑的界面包括理想界面、滑动界面以及柔性金属电极层增强界面；一般各向异性压电介质中任意形状的Eshelby夹杂与椭圆孔洞的相互作用。

Based on complex single piezoelectric layer's film bulk acoustic resonator, a new kind of complex double piezoelectric layers' FBAR is proposed. This structure can greatly improves the flexibility of the selection of piezoelectric materials for FBAR.

在复合单压电层薄膜体声波谐振器的基础上，提出了一种新型的复合双压电层FBAR，它可以大大提高压电材料选择的灵活性。

"Yes, now you can give yourself airs," she said, you have got what you wanted.

"对了，您现在高兴了，"她说道，这是您所期待的。

Then the LORD said to me: Rebel Israel is inwardly more just than traitorous Judah.

上主于是对我说：＂失节的以色列比失信的犹大，更显得正义。