电流变技术与应用

电流变效应是一种奇特的效应。电流变液在外加电场的作用下产生粘度的连续变化，可以在液体和固体间快速并可逆地转化。这种特性预示着其潜在的广泛应用，因而引起了人们极大重视，本文介绍了电流变效应、电流变材料和电流变的式程应用。     

一种电流变（ER）材料的研制与电流变性能测试

本文对一种电流变液体的颗粒材料和基础液的研制工艺进行探讨，并对其电流变性能进行了测试。     

高压外加电场的自动控制及其应用

为进一步探索电流变技术在液压控制中的应用，本文采用了计算机自动控制电流变液的外加电场，提高了实验的安全性，减少了手工调压所引起的误差。利用此计算机辅助装置，对电流变效应进行了实验研究。实验结果与理论分析基本一致。     

电流变液体平板缝隙阀式流的研究

电流变阀类装置在轴向压力作用下的缝隙流动方式是电流变液的主要工作状况之一。本文以理论分析为基础，对电流变液体的缝隙流进行深入研究，从而建立其流动模型，并以试验为手段对流动模型的参数确定方法进行完整的描述。     

磁流变流体--新型智能流体材料

本文针对磁流变流体的发展概况、工作机理、流变特性及应用前景进行介绍，尤其在流变特性上同电流变流体和铁磁流体进行了比较，为人们了解和研究这种新型的智能流体材料提供了参考。     

电(磁)致流变材料的发展

智能材料及其器件是当今高技术材料研究的重要领域之一,电（磁）致流变材料是智能材料的一个重要分支。本文介绍了电（磁）致流变材料一电流变液、磁流变液的特性、应用及它们的最新发展情况。     

以环氧树脂为母液的悬浮液的电流变效应

研究了以淀粉，二氧化锡和三氧化铝为分散相颗粒，以非油类的环氧树脂为母液的悬浮液，在交流电场作用下的电流变效应及其影响因素，如电场强度，悬浮液浓度，颗粒粒径等，还研究了漏电流密度及其影响因素，实验表明，以环氧树脂为母液的悬浮液具有明显的电流变效应，非油类的环氧树脂可作为电流变液的母液。     

电流变技术在车辆减振装置中的应用研究

电流变技术应用于车辆减振控制具有响应速度快、阻尼无级可调、能耗低等特点,可以通过适当的控制规律实现对结构振动的最优控制。本文通过对充气式电流变减振器原理进行分析,讨论了减振器阻尼力计算公式,它包括电流变液基础粘度引起的本底阻尼力、由电场作用引起的电致阻尼力和气室气体引起的压力三部分。开发了一种结构简单的充气式电流变液体减振器,对影响减振器性能的主要结构参数进行了分析讨论,给出了减振器设计中参数选择的一般原则和应注意的问题。通过台架实验,对所设计的电流变液体减振器性能进行了考察,得到了较好的示功图和速度特性曲线,为车辆路试奠定了基础。     

电流变液(ERF)换向阀的设计

研究了电流变液换向阀的设计原理，设计方法一并对该换向阀的性能进行了分析。     

电流变阻尼器辅控的位移补偿装置构架设计

介绍了电流变液及评价参数,分析了电流变阻尼器数学模型,提出了利用电流变效应辅助控制液压元件的构架设计思路,用于系统的位移补偿,为构造新型机电液智能控制元件或伺服系统提供技术储备.     

基于控制理论的电流变流体动力元件的特性分析

介绍了含ER技术的机械系统控制方程的建立方法。应用控制理论建立了电流变流体动力元件的控制方程，并对其进行了一般性分析及参数优化设计。     

电流变阻尼器非均布场控电极设计及其电场仿真

均匀电场控制下的电流变液在高剪切速率载荷作用下会丧失电流变控制能力,无法满足高速冲击载荷电流变阻尼器的应用需求。现有研究表明采用具有与电流变液流动方向平行的电场分量的非均布电场控制会改善这一问题。设计一种圆环型交指状电极结构,能够形成具有平行电场分量的非均布控制电场,并以电流变作用空间内有效电场强度值来表征非均布控制电场,通过COMSOL Multiphysics软件仿真分析了电极结构几何参数对有效电场强度的影响规律。仿真结果表明:有效电场强度最小值随电极宽度的增加而减小,随绝缘宽度的增加而增加。研究结果对非均布场控电流变阻尼器的电极结构设计提供了依据,并为非均布场控下电流变液其他应用提供了参考。     

高冲击下电流变阻尼器多物理场建模与仿真

针对将电流变阻尼器应用于冲击载荷下的火炮反后坐装置,阻尼器采用固定电极板式结构,利用COMSOL Multiphysics多物理场软件,建立电流变阻尼器的二维轴对称几何模型,根据计算流体动力学模块,得到不可压缩的电流变流体层流仿真。分析高速冲击下电流变流体在环形间隙的流动情况,并且在变化的电场耦合作用下,仿真计算出电流变阻尼器输出阻尼力的大小,同时也研究阻尼器结构参数对输出阻尼力的影响。仿真结果表明:在1~5 k V范围内增加极板电压,环形通道流体速度降低1.03 m/s,总输出阻尼力提高375.9 N;在电场强度为5 k V/mm情况下,阻尼通道有效长度增加25mm,阻尼力由828.2 N增大至1 950.8 N;保持阻尼通道长度不变,环形间隙增大1.5 mm,阻尼力下降至113.3 N。     

Investigation into electrorheological fluid-assisted polishing

Electrorheological fluid (ER fluid) is a functional fluid with the property that its viscosity can vary with the applied electric field strength. This paper investigates a polishing method using the electrorheological fluid, known as ER fluid-assisted polishing, for the finishing of micro dies of tungsten carbide alloy, which are used for the mass production of micro aspheric glass lens. The machining principle of the ER fluid-assisted polishing is introduced. By proper design of experiments based on a Taguchi orthogonal array and by multi-variable linear regression, empirical models are developed for evaluation of the effect of the process parameters on the material removal depth and surface roughness obtained in the ER fluid-assisted polishing. Further experiments are conducted to confirm the validity of the developed statistical model by comparing the model predictions with the experimental results and meanwhile the influences of the process parameters on the polishing performance are revealed.     

An investigation of effective area in electrorheological fluid-assisted polishing of tungsten carbide

Electrorheological (ER) fluid-assisted polishing is a novel polishing method for the finishing of micro-aspheric lens, dies and mirror. This paper investigates the effective area in the ER fluid-assisted polishing of tungsten carbide, which is used as the die material for the mass production of micro-aspheric glass lens. The effective area is defined as the area in which the abrasive particles concentrated in the vicinity of the tool tip makes the effective material removal from the workpiece. The electric field strength applied between the tool and the workpiece is analysed. The interacting forces between particles suspended in the electrorheological fluid are calculated. An approach is proposed to predict the effective area and the experiments are conducted to confirm the validity of the proposed method.     

The electromechanical principle of electrorheological fluid-assisted polishing

An up-to-date abrasive polishing process using electrorheological (ER) fluid, known as ER fluid assisted polishing, is potentially useful in the surface finish of three dimensional micro or meso-scale devices. For a more detailed understanding of this process, the electrostatic principle of how an ER fluid functions on the polishing is described. Dielectric particles suspended in a dielectric fluid are polarized with the application of an electric field, and they experience the dipolar interaction force each other and the translational force along the field, defined as dielectrophoresis due to the non-uniform electric field. As a result of the calculations of the exerted forces on the ER and abrasive particle suspended in silicone oil, ER particles strongly attract the abrasive particles as well as each other when they are aligned with the electric field. Because this attraction force is much higher than the dielectrophoretic force, abrasive particles adhere to ER particles which concentrate on a tool along the field lines. The behavior of particles is observed by the CCD camera, and borosilicate glass is polished to evaluate machining performance.     

Chatter suppression based on nonlinear vibration characteristic of electrorheological fluids

Self-excited chatter is a serious problem in machining shops and its frequency is always near the resonant frequency of the machining system. This paper proposes a novel design method for a tunable-stiffness boring bar containing an electrorheological (ER) fluid to suppress chatter in boring. The ER fluid undergoes a phase change when subjected to an external electrical field and serves as a complex spring behaving nonlinearly in the structure. The deformation modes of the ER fluid are dependent on the applied electric field and the strain amplitude. As a result, the global stiffness and energy dissipation properties of the boring bar under an electric field change drastically at different amplitudes of vibration. It is found that the amplitude of chatter can be prevented from increasing by using the nonlinear vibration characteristic of the ER fluid. It is shown experimentally that the chatter can be suppressed under a certain range of the electric field related to the cutting conditions.