【作者】 付华；

【导师】 吴根茂； 傅周东；

【作者基本信息】 浙江大学 ， 机械电子工程， 2004， 博士

【摘要】 MR材料具有屈服应力大、响应速度快、能耗低、显著的流变效应、对污染不敏感等特点，逐渐成为了新型阻尼器的首选材料。MR(磁流变体)阻尼器是根据MR材料具有磁流变效应的特性，通过磁场来控制MR流体的流动特性，以实现阻尼力控制。这与通过改变阻尼通道面积的来控制阻尼器的阻尼力传统的半主动阻尼器原理截然不同。开创了半主动阻尼器研究的新思路，具有重要的研究意义和广泛的应用前景。 本文根据磁流变体技术的发展趋势，针对微米级MR材料存在着不稳定的缺点，选择Nano-MR为主要研究对象。系统地研究了磁流变阻尼器技术：包括磁流变效应、磁流变材料的性质、MR阻尼器系统理论、阻尼器的设计准则、实验研究、阻尼器的动力学模型。根据高速电梯发展现状，选择高速电梯减振为应用对象，研究出高速电梯减振系统-Nano-MR阻尼器，并对电梯进行控制实验，旨在推进MR阻尼器和高速电梯减振系统的研究。 本文分为八章。 第一章，以大量的国内外文献为基础，全面综述了MR材料、MR阻尼器和高速电梯减振系统的研究现状。阐述了开发、研究Nano-MR阻尼器以及高速电梯减振系统的重要性和必要性。确定了具有发展前途的Nano-MR阻尼器和高速电梯减振系统为主要研究内容。 第二章，介绍了磁流变现象、机理和结构。理论分析了MR的稳定性，根据微米MR材料存在的稳定性差的问题，选择Nano-MR材料为研究对象。对不同体积比的Nano-MR进行了稳定性实验。讨论了Nano-MR的顺磁性和磁松弛问题。分析体积比对MR粘度的影响。并进行了分析体积比对MR粘度的实验和温度对粘度影响的实验。比较Nano-MR和Micro-MR的特性。最后进行了磁流变特性测试实验。得到Nano-MR的流变特性，为Nano-MR阻尼器的研究奠定了基础。 第三章，首先研究了Nano-MR阻尼器线圈(螺旋线圈)产生的电磁场，接着讨论了阻尼器设计中若干电磁学问题(包括磁芯材料的性质、磁芯材料的选用、和阻尼器磁路的能量损失)，然后给出Nano-MR阻尼器的磁路设计、电路设计的计算公式。并对计算结果进行了实验验证。为Nano-MR阻尼器的磁路设计提供了计算方法。 第四章，根据MR阻尼器的工作模式，分别建立了这几种工作模式的MR阻尼器的理论模型。推导出Nano-MR阻尼器阻尼力的计算公式。讨论了阻尼器结构参数对阻尼特性的影响。有限元仿真了阻尼器中Nano-MR流体的流场和应力分布。为Nano-MR阻尼器设计计算和结构设计提供了理论依据。 第五章，针对MR阻尼器设计研究的不足，首先对各种MR阻尼器的结构形式和特点进行分析，接着讨论了MR阻尼器结构和结构参数设计。从而设计出用于电梯减振的MR阻尼器，并总结出MR阻尼器的设计准则。以期待为MR阻尼器的设计奠定基础。 第六章，理论分析了阻尼器的示功性、速度特性等工作特性，说明了这些特性对于描述阻尼器工作性质的重要性。分别进行了一系列实验:演示实验，示功特性和速度特性实验，加速度特性实验，最后进行了MR阻尼器响应速度的实验。其中加速度特性实验包括:负载对加速度特性影响实验、电流对加速度特性的影响实验、正弦激励下的加速度和阻尼特性实验。实验结果反映了实际MR阻尼器的基本特性，说明磁流变体基本符合Bingham模型描述的本构关系。得出MR阻尼器的响应时间为毫秒级。 第七章，介绍了提高高速电梯舒适性的发展概况，分别就人体舒适性和电梯舒适性的标准进行讨论，认为电梯的横向振动是提高高速电梯舒适性的重要影响因数之一。在电梯横向振动分析的基础上，用MR阻尼器作为减振器分别采用继电器控制，改进型继电器控制以及模糊变结构控制对电梯进行振动控制实验。实验表明减振效果较好，其中模糊变结构控制效果最为明显。 第八章，概括课题的主要研究成果和课题的创新点，并展望了今后需要开展的研究工作。 总结全文，本课题从纳米材料、功能材料、电磁学、流变力学、固体力学等方面出发，对Nano一MR流体的流变特性和Nano一MR阻尼器的阻尼特性性质进行了全面的研究。总结了MR阻尼器的设计准则。设计出电梯用Nan。一MR阻尼器。并对高速电梯横向减振系统一Nano一MR阻尼器进行了几种减振控制实验，实验表明作为新型的高速电梯减振系统一Nano--MR阻尼器是成功的。关键词:MR阻尼器，Nano--MR，高速电梯，振动控制，磁路，阻尼力更多还原

【Abstract】 Because there are high yield stress, high reflect speed rate, low energy consumption, small pollution effect, etc., MR (magnetorheological ) becomes first choice for damper material. Principle of tradition damper is that change damper force with damper channel adjustment. There are the defects of complex construct and long reflect time on tradition damper. The principle of MR damper is change damper force by modifying fluid nature. It develops a new idea for damper and has significant research value and application prospect.Based on present development of high speed elevator and MR material technique , MR damper techniques have systemically studied on the dissertation. It includes mechanism of magnetorheology, nature of MR, theory of MR damper, design method, damper experiment, and vibration control of high speed elevator. All of those in order to promote development of MR damper and high speed elevator reducer technique. The main content of each chapter is as following.The first chapter according to large sums of documentation and information, overview the development of MR, MR damper, high speed elevator. Represent important and necessary of research to MR damper and vibration damp system of high speed elevator. Main content of the project is determined as MR damper and vibration damp system of high speed elevator.The second chapter introduces MR phenomenon, MR mechanics, MR fabric, theoretically analyses stability of MR. Relative experiments have done. In order to understand nature of MR. Some researches are done, such as analysis of paramagnetic phenomenon and paramagnetic relaxation, influence of volume percent to viscosity. Finally the project finished viscosity-temperature and nature of MR. All of those lay foundation of research on MR damper.Main study is magnetic field problem in the third chapter. The dissertation studies magnetic field of MR damper’s coil, then discusses the problems ofelectromagnetics in MR damper design. The paper deduces formula of magnetic circle and electric circle of MR damper and certified those through experiment.According to the model of MR damper, these mechanical modes are built in the fourth chapter. The project discussed influence of damp force to the parameter of MR damper and carried finite element analysis of MR flow field and shearing stress. These works established the study foundation of MR damper.In the fifth chapter, the dissertation designed the MR damper for elevator through analysis of structure and character of MR damper. On basis of experience of practice deign, the paper put forward a design guide rule of MR damper.On the basis analysis on diagram of work and speed character of damper, the dissertation narrated the important of the natures in the sixth chapter. A series of experiments have done. Those include demonstration one, diagram of work experiment, speed character experiment of damper, acceleration experiment, and reflection experiment. The experiments gained the character of MR damper, proved that MR coincides Bingham model constitutive equation and reflection time of MR damper can reach microseconds.After introducing development of elevator amenity, the seventh chapter discussed elevator amenity standards and considered that lateral direction vibration is one of main aspect on elevator amenity. Based on analysis of elevator vibration, elevator vibration control has done by relay method, modified relay policy and fuzzy variable structure strategy. The experiment indicates the result by fuzzy variable structure strategy control is best. The research shows that Nano-MR damper as elevator vibration reducer is success.The eighth summarizes the main achievements and innovation points of the project, and prospects the demand research work needed for the future.Summarizing the dissertation, project study characters of Nano-MR and the damper put forward the criterion based on nanometer technology function material, electromagnetism, rheology, mechanics aspects. Finally the project design lateral vibration reducer of high speed elevator. These fill-up the blank.更多还原