书本式压电作动器的特性分析

在考虑粘接层影响的情形下，利用层合梁理论导出了柱形弯曲书本式压电作动器的作动力以及机电耦合系数的数学表达式，并通过数值仿真分析揭示了机电耦合系数与压电层层数、压电层厚度以及粘接层厚度间的关系。这些结果为书本式压电作动器的结构综合优化设计提供了理论基础。     

真空断路器磁力驱动机构的静态磁路分析与计算

进行了真空断路器磁力驱动机构的磁路设计 ,并采用磁路法设计磁力计算软件 ,并就有关问题进行了讨论。     

定向BaTiO3晶须/PVDF压电复合材料的制备及性能研究

以高度定向的BaTiO3晶须作为活性相、聚偏氟乙烯(PVDF)作为基体制备了压电复合材料，研究了该复合材料的介电和电学性能，研究结果表明，以BaTiO3作为活性相的晶须复合材料与粉末复合材料相比，其介电常数(ε)、压电常数(d33)和剩余极化率(Pr)大大提高，而其损耗因子(tanδ)具有相反的趋势，对晶须复合材料，沿晶须定向方向的ε、d33和Pr的值比晶须平行方向要高得多，分析了产生这些差别的原因。     

硅基AlN应力和压电极化研究

通过XRD和Raman谱研究了用金属有机化学气相沉积 (MOCVD)的方法在Si( 111)面上生长的AlN薄膜层上的应力和压电极化 ,Raman谱观察到两个声子峰位分别在 619.5cm- 1 (A1 (TO) )和 668.5cm- 1 (E2 (high) )。通过光学声子E2 (high)的频移为 13cm- 1 计算得到AlN薄膜上的双轴压应力为 5 .1GPa ,在z轴方向上和在垂直于z轴方向上的应变分别为εzz=6 7× 10 - 3和εxx=-1 1× 10 - 2 ,产生的压电极化电荷PPE=2 .2 6× 10 - 2 c·m- 2 ,这相当于在Si的表面产生浓度为 1.41× 10 1 3c·cm- 2 的电子积累。同时 ,实验还发现在MOCVD生长过程中存在Si原子的扩散 ,在界面处形成了一个过渡层 ,过渡层主要以Si原子取代Al原子的位置并形成Si-N键为主。     

执行器饱和单输入线性系统的分析和设计

若线性系统可被某状态线性反馈全局渐近镇定 ,饱和介入反馈后 (具有反馈的 )系统稳定性或得以保持 ,或降为区域渐近稳定 .本文作者就这一问题给出简洁判据 ,且对后者计算其不变吸引 (超 )椭球 ;在此基础上用叠代法求取使椭球尽量大的反馈增益 ;最后用算例说明方法的有效性 .     

Perturbation method of the piezoelectric fracture mechanics considering the permittivity of the medium in the crack gap

In this paper, the problem of the cracks with arbitrary forms in piezoelectric material is studied. The permittivity of the medium in the crack gap is considered. Except the collinear cracks, this boundary condition is too difficult to deal with; therefore, a perturbation method is recommended. By the way, the electric boundary conditions of electric fracture mechanics are discussed. For example, a small parameter solution of a crack is given and compared with the known `exact' (it will be discussed later) solution. This result shows that the impermeable or permeable conditions are only the boundary conditions for the first approximations of the perturbation solutions.     

Vibration Analysis of Tb-Dy-Fe Magnetostriction Actuator and Transducer

In this paper, theoretical analysis of longitudinal free vibration was carried out for Tb-Dy-Fe series magnetostrictive actuator and transducer. The formulations considered two constitutive laws; in one we employ the standard square nonlinear constitutive equation of magnetostriction and in the other we employ the linear piezomagnetic equation. The results obtained from the nonlinear equation can be reduced to the linear piezomagnetic equation when the amplitude of the excitation magnetic field provided by the coil is very small compared to the bias magnetic field and its frequency does not induce resonance of the system. For the case of a relatively large excitation magnetic field, which usually exists for an actuator, the nonlinear constitutive equation should be adopted in order to provide an accurate prediction for the design and analysis of actuator and transducer. Another important aspect is the resonance of the Tb-Dy-Fe series transducers that was revealed in the analysis using the nonlinear constitutive equation. The resonance not only appears at the natural frequencies of the system, but also arises when the frequency of excitation current in the coil happens to be half of one of the natural frequencies of the system. This conclusion cannot be reached using the linear piezomagnetic formulation.     

ULTRA‐FINE TRACKING CONTROL ON PIEZOELECTRIC ACTUATED MOTION STAGE USING PIEZOELECTRIC HYSTERETIC MODEL

The tracking control accuracy of the piezoelectric actuator (PEA) is limited due to its inherent hysteresis nonlinearity. A new piezoelectric‐actuator model is synthesized based on two first‐order transfer systems in parallel with two tuned parameters determined from one experiment. Two open‐loop tracking controllers are implemented with the proposed model to compensate the hysteresis of linear positioning. Numerical simulations and experimental tests on the tracking of sinusoidal and triangular waveforms with signal frequencies ranging from 1Hz to 30 Hz are revisited and compared with the conventional Bouc‐Wen and Duhem models. Experimental results reveal that the RMS tracking error can be reduced to less than 2% of the maximum traveling distance without any feedback sensor. When a piezoelectric actuated on a two Degree‐Of‐Freedom (DOF) monolithic motion stage was employed, the RMS tracking error was 50 nm within the measured sensor accuracy.     

压电驱动晶体的特性研究

压电陶瓷迟滞特性是影响压电陶瓷驱动器位移输出精度的主要因素。在仔细研究现有的解决方案的基础上，采用Preisach模型对压电的迟滞性进行建模，并进行了相应的实验研究。实验结果证明该方法可以很好地降低压电陶瓷迟滞特性对位移输出性能的影响。而且采用压电陶瓷位移输出不回复到初始0电压状态的处理方法能够更地吻合实际情况。     

新型惯性式压电驱动机构的研究

基于控制移动机构和支撑面之间摩擦力的方法,提出了新型惯性冲击式压电陶瓷驱动机构的研究方案.分析了驱动机构的工作原理,驱动电压与驱动力、位移之间的关系,设计、制做了可实现直线往复运动的压电微型驱动器结构,并作了相关的性能测试.实验结果表明,采用简单的对称信号波形能驱动机构运动.直线驱动器最高速度可达1 mm/s,最大步长分辨率为20 nm,最大承载能力为1 000g.