电流变液在结构振动抑制中的应用研究

根据结构抑振的应用要求,研制出了几种零场粘度低、有场粘度变化梯度大的电流变液,并设计制作了电流变液静态屈服应力测试仪,测试出了所研制的电流变液的静态屈服性能随电场强度和液体组份比变化的曲线。利用自制的电流变液,对含电流变液的夹层板振动进行了单模态抑制,由此得出电流变液对振动机理在于：一方面通过电流变阻尼效应降低结构振动响应的幅值,特别是共振峰的幅值;另一方面通过电流变刚度效应使结构的有效刚度增加,结构的共振点发生移动,从而使结构在共振频率激励下的振幅大大降低。对本文的夹层板模型,在３ｋＶ／ｍ ｍ 的电场强度下,第三阶模态的响应幅值降低了９０％ 。     

电流变液在电场中受挤压时的力学行为

研究了电流变液的准静态挤压过程,测试了在不同外加电场下挤压时电流变液所能承受的压缩应力随压缩量的变化曲线,并利用由Williams等人基于广义双粘度模型推导出的电流变液压缩应力与屈服切应力之间的关系式计算了压缩应力随压缩量的变化,其结果与试验测试的曲线基本吻合,说明电流变液受挤压时的力学行为可以用双粘度流体力学理论作出较准确的描述和预测。     

电磁流变液流变特性测试技术的研究进展

电流变液和磁流变液由于其良好的可控性能和力学性能而在工程上具有广阔的应用前景。电流变液和磁流变液流变特性的测试是电流变技术和磁流变技术的一个重要方面。简要介绍了电流变液和磁流变液及其流变特性测试的主要参数，阐述了各种测试方法的原理及其测试仪器和试验装置，分析了各种测试方法的优缺点，探讨了测试技术中存在的一些问题。     

电流变减振器在数控车床上的应用研究

电流变技术是电流变现象或电流变效应在工程实践中成功应用的一门技术,为了提高数控车床的加工精度,在分析了数控车床振动特性的基础上,设计了一种基于电流变液的数控车床刀具减振器,应用于抑制切削振动和振动控制。由于电流变液快速、可逆固液化以及易于控制的特性,为了能将数控车床上的振动量减少一个数量级,可以通过选择合理电流变液阻尼器的相关参数和正确设计振幅实时控制系统的方法,从而满足对数控车床减振的要求。     

电流变液智能材料在工程技术中的应用

简要介绍了电流变效应的机理和电流变液的特性,归纳了电流变液在工业中的应用,展望了电流变液广阔前景。     

基于ER阻尼的WEDM电极丝恒张力微机控制

电流变液是一种可控智能阻尼介质,其表观粘度和剪切屈服应力随外加电场发生快速变化。设计了一种以ER阻尼器为执行元件的恒张力微机控制系统,系统响应快,较好地解决了电火花线切割加工过程中的张力测量和控制精度问题,实现了电极丝的恒张力控制。     

基于电流变液换向阀的设计与仿真

该文阐述了电流变液作为工作介质应用于电流变液换向阀的工作原理,设计了一种ER桥式的电流变液换向阀数学模型,对电流变阀控制系统进行了理论分析,并进行了仿真。     

电流变液力学特性的实验研究

电流变液的力学性能参数是评价电流变液的性能指标之一 ,也是含电流变液智能结构建模所需的基本参数。对电流变液这种新兴的材料 ,其力学参数测试尚没有成熟统一的方法。本文研制了一系列电流变液力学参数专用测试仪器 ,并对所研制的电流变液的基本力学参数进行了系统的测试。结果表明 ,电流变液的拉伸模量和剪切模在屈服转捩前后有明显差异。本文所研制的电流变液在应力应变曲线上无过冲现象 ,其强度满足一定条件下的工程应用要求     

电流变液技术在液压控制系统中的应用

电流变液是一种流变特性可受外加电场控制的智能材料,该文阐述了电流变液材料的组成、特性和作用机理,介绍了电流变液技术在液压控制系统中的应用.     

电流变离合器用电流变液探讨

文章分析了电流变离合器用电流变液的工作特点，失效原因，指出了它与缓冲器，隔震器用电流变液的不同之处，说明了两相电流变液用在离合器上的不足，明确了电流变离合器用电流变液应以单相液晶的混合液为发展方向。     

Determination of the Bingham parameters of an electrorheological fluid in an axial flow concentric-cylinder rheometer

Electrorheological (ER) fluids are fluids that undergo changes in their rheological properties in the presence of an applied electrical field. The change in the flow properties with an applied electrical field has led to their being investigated for use as ‘smart’ lubricants. The Bingham model is currently used to describe the behaviour of these fluids. In this work, the Bingham model parameters of a commercially available ER fluid are obtained using an axial flow concentric-cylinder rheometer. Two methods are used to determine these parameters. One is the Weissenberg (—Rabinowitsch) method applied to thin annular slits, to obtain corrected stress—strain rate information. The other method involves directly fitting the velocity—pressure curve data to the axial flow rate equation of a Bingham fluid through concentric cylinders. The results obtained by these two methods differ by as much as 49.4 and 63.5% for the yield stress and viscosity, respectively. It is observed for this ER fluid that the yield stress increases according to a power law relationship with the applied electrical field. The viscosity appears to decrease linearly with an increase in the applied electrical field.     

电流变体在密封中的应用研究

本文根据电流变体在一定电压状态下所具有的固化特性，将电流变体开发诮地密封装置中以解决工程实际中流体系统的密封问题。试验表明电流变体在密封中应用具有一定的潜力。本文的研究为电流变体的工程应用开拓了一个新的领域。     

A study on the control characteristics of ER valve-FHA system and durability test

In this paper, making the best use of the features of the electro-rheological (ER) valve, a two-port pressure control valve using ER fluids is proposed and manufactured. The ER-Valve characteristics are evaluated by changing the intensity of the electric field and the number of electrode. As only with electrical signal change to the ER-Valve in which ER fluid flowing, ER fluid flow is controlled, so development of simple ER-Valves have been tried. The ER-Valves and pressure drop check method are considered to be applied to the fluid power industry. Using the manufactured pressure control valve, a one-link manipulator with FHA (Flexible Hydraulic Actuator) is driven. As a result, it is experimentally confirmed that the pressure control valve using ER fluids is applicable to use in driving actuator. If it applies characteristics of the ER fluids, it will be able to apply in the control system for the ER Valve which occurs from industrial controller. After having durability test, shear stress increased regularly because of starch particles crushed by pump and particle size that was almost the same. Moreover, Ra of copper electrode increased about 1.56 times rather than before those of performing durability test, and Rz increased about 2.2 times.     

Squeeze film lubrication of a short porous journal bearing with couple stress fluids

This paper presents the theoretical investigations of the rheological effects of the couple stress fluids on the static and dynamic behaviour of the pure squeeze films in the porous journal bearings. The present study predicts the effects of percolation of the polar additives (microstructures) into the porous matrix on the performance of squeeze films in the porous journal bearings. The most general modified Reynolds-type equation is derived for a porous journal bearing with no journal rotation. The analysis takes into account of the tangential velocity slip at the porous interface by using the BJ-slip condition. The cases of a short porous journal bearing under a constant applied load and that under an alternating load are analyzed. As compared to the Newtonian lubricants, the lubricants which sustain the couple stresses yield an increase in the load carrying capacity. Under a cyclic load the couple stress fluids provide a reduction in the journal velocity and an increase in the minimum permissible height of squeeze films.     

电流变技术研究及展望

电流变液是一种新型智能材料,在机械领域有广阔的应用前景。介绍了具有高抗剪强度的电流变液材料配制,体积比率以及温度对电流变效应的影响,电流变液的拉伸、压缩和剪切力学特性、剪切作用下的动态响应,及一些应用基础研究。指出电流变效应机理的不清楚和力学性能的不准确描述是阻碍电流变液广泛应用的重要因素,是今后电流变技术研究中必须克服的问题。     

Development of a laboratory test device for electrorheological fluids in hydrostatic lubrication

Electrorheological (ER) fluids exhibit changes in their rheological behaviour in the presence of an external electric field. Research and development activities related to ER fluids and their applications have increased dramatically during the last few decades. If commercialised, ER fluids could have a significant impact on hydraulic equipment, and be utilised in the automotive, marine, aerospace, robotics, and machinery industries. The objective of the present study is to demonstrate the feasibility of using ER fluids to produce ‘smart’ lubricants that can control friction and wear of sliding components. The ER lubricant effect is demonstrated using a unique test machine that utilises hydrostatic lubrication. It is found that the friction torque increases by as much as 30% when a voltage of 2000 V is applied to an ER fluid in the newly developed test machine.     

一种新型的ER液体剪切性能测试装置

ＥＲ液体是一种在电场作用下可改变其剪切粘性的液体、本文介绍了一种可用来考察其剪切特性的装置，利用该装置不仅可分析ＥＲ液体的力矩传递特性与电场强度、剪切速率、电极间距离等因素的关系，并且稍加改进还可利用它来考察ＥＲ液体对外电场的响应时间。这对高性能ＥＲ液体的研制及其实际的工程应用都是非常必要的、最后通过对由硅油－硅胶组成液体的剪切试验，验证了该装置的有效性。     

电流变液机理及其研究现状

电流变液是一种在外加电场作用下表观粘度发生显著变化的液体，近年来，作为一种智能流体引起研究人员的广泛重视，本文阐述了电流变液的组成，作用机理，影响流变的因素及其在工程中的应用，介绍了电流变液在国内外的研究现状，并在此基础上提出了几个值得重视的问题。     

新型电流变制动器的结构初步设计及性能分析

根据电流变(electro-rheological，ER)流体的力学性能并结合原有制动器的特点，设计一种能够更大幅度提高ER制动器制动力矩的新型ER制动器，给出其结构示意图和制动力矩的计算公式。通过对DF11机车制动时间和制动距离的仿真计算，显示在同样的外加电场和ER流体材料的情况下，新型ER制动器可大大缩短制动距离和制动时间，其制动性能是非常显著的。