复合场下磁流变液圆筒模型剪切应力特性研究
发布时间：2019-03-05 18:54
【摘要】：磁流变液是一种新型的智能材料,在无磁场的情况下表现为低粘度的牛顿液体特性,一旦加入磁场,便会在毫秒级时间内响应变为固体或者类固体状态,这种特性被称为磁流变效应。目前的众多磁流变液产品一般都是对磁流变液的力学特性的应用,因此磁流变液的力学性能研究也是磁流变液研究工作的一个重要方面。在磁流变液众多力学特性应用中,当属剪切应力特性应用最为广泛,因此磁流变液的流变特性研究也集中于此。磁流变液剪切应力特性输出一般受到磁场、温度场、重力场、剪切速率、剪切应力方向、导磁性颗粒的大小形状与分散情况、工作时间、装置结构与材料特性、工作面表面粗糙度与纹路等众多因素影响。其中磁场是磁流变液磁流变效应的必备因素,而磁流变液实际工作过程中会有大量的机械能转化为内能从而引起磁流变液的温升,或者温度场的不均匀分布。因此,磁场和温度场变化在磁流变液影响因素中最为突出,而磁流变液实际工作一般都处于在磁场、温度相互耦合的环境之中。本文对磁流变液及影响其力学特性输出的主要因素作了简要介绍,并从磁场、温度场这两个影响因素角度,综述了磁流变液剪切应力特性理论研究进展和磁流变液流变特性检测技术的现状和发展趋势,分析和比较了现有流变特性理论和检测方法的优势以及不足之处,针对复合场下磁流变液的特点,并提出了本文的研究目的、研究方法、研究意义。文章根据磁流变液试验装置设计和材料性能的检测需要,介绍了Bingham模型、Bingham双塑性模型、Herschel-Bulkley模型和Eyring本构模型来描述磁流变液流变学特性理论。经过分析和比较,选取了参数较少,物理意义较为明确的bingham模型作为复合场内磁流变液流变特性理论模型建立的基础。并从磁流变液的工作模式出发,介绍了管道流动式剪切模型、圆盘剪切模型、圆筒剪切模型,比较选择了圆筒剪切模型作为实验装置的力学模型基础。通过有限元分析法,对圆筒剪切模型中磁流变液微元进行了受力分析,得到了磁流变液微元的力学模型,进而分析得到了圆筒剪切模型中磁流变液的力学和运动学规律。最终总结得到了圆筒剪切模型中磁流变液剪切应力和剪切速率的测量方法,并有效得避免了预屈服区间对磁流变液检测的影响。从复合场的角度出发,对磁流变液工作过程中磁场和温度场两个场复合作用对磁流变液剪切应力输出特性的影响规律进行了理论分析,以bingham模型、粘温特性、居里公式、磁流变液磁场强度与流变特性变化规律四个方面为基础进行理论推导,得到了复合场内磁流变液应力输出理论模型。经过理论分析发现温度场对磁流变液的影响的本质乃是改变了磁流变液中软磁性颗粒的导磁率和载液的粘度,进而改变了磁场强度,导致应力输出改变。以圆筒剪切模型、磁场理论分析、温度场理论分析为基础设计并研制了一套复合场下磁流变液流变特性研究装置,并通过ansys仿真分析,对装置的内磁流变液的温度场及磁场分布规律进行了仿真模拟。仿真证明了实验装置能够很好的为磁流变液剪切应力特性检测提供均匀稳定的磁场和温度场,复合实验需求。设计了磁场和剪切速率影响实验测量、磁场和温度场复合实验测量过程两个实验,测量了大量的实验数据。从实验的角度对磁流变液剪切工作过程中温度场、磁场复合影响规律进行了研究。数据分析发现,磁流变液剪切应力输出随着磁场、剪切速率上升而上升,随着温度场的上升而下降。相比较而言,磁场强度的上升对应力输出的影响要远大于剪切速率上升的影响。研究还发现,磁场强度越大的情况下,剪切应力随着温度场上升而下降的量越大。这与磁场越大时,温度上升对磁场影响越大的规律相一致。实验数据分析表明,将温度场的影响通过居里公式、粘温特性公式转化为磁场和粘度影响的理论与实际相吻合,证明了理论推导的正确性。以磁场和温度场理论模型为基础,设计了温度场补偿实验。通过磁场的微量上升补偿温度场上升带来的磁流变液剪切应力下降影响。通过实验发现,磁流变液剪切应力下降量由原来的30%/100℃降低至3%/100℃,基本降到了可接受范围内,也进一步证明了磁场温度复合场对磁流变液影响理论的正确性。
[Abstract]:The magneto-rheological fluid is a new type of intelligent material, which exhibits a Newtonian liquid characteristic of low viscosity in the absence of a magnetic field. Once the magnetic field is added, the response becomes a solid or solid state in the millisecond time, which is referred to as the magneto-rheological effect. At present, a large number of magneto-rheological fluid products are generally applied to the mechanical properties of the magneto-rheological fluid, so that the mechanical property research of the magneto-rheological fluid is also an important aspect of the research of the magneto-rheological fluid. In that application of a plurality of mechanical properties of the magneto-rheological fluid, the application of the shear stress characteristic is the most widely used, and therefore, the rheological property of the magneto-rheological fluid is also concentrated. The output of the shear stress characteristic of the magneto-rheological fluid is generally influenced by the magnetic field, the temperature field, the gravity field, the shear rate, the shear stress direction, the size and shape and the dispersion condition of the magnetic conductive particles, the working time, the device structure and the material property, the surface roughness and the grain of the working surface, and the like. In which the magnetic field is a necessary factor of the magneto-rheological effect of the magneto-rheological fluid, and a large amount of mechanical energy is converted into internal energy in the actual working process of the magneto-rheological fluid so as to cause the temperature rise of the magneto-rheological fluid or the non-uniform distribution of the temperature field. Therefore, the change of the magnetic field and the temperature field is the most prominent in the influence factors of the magneto-rheological fluid, and the actual operation of the magneto-rheological fluid is generally in the environment in which the magnetic field and the temperature are coupled with each other. In this paper, the main factors that influence the output of the magneto-rheological fluid and its mechanical properties are briefly introduced, and the research progress of the shear stress characteristic of the magneto-rheological fluid and the current situation and development trend of the rheological property detection technology of the magneto-rheological fluid are summarized from the aspects of the magnetic field and the temperature field. In this paper, the advantages and disadvantages of the current rheological property theory and the detection method are analyzed and compared, and the characteristics of the magnetorheological fluid under the compound field are analyzed and compared, and the research purpose, the research method and the research significance of the present invention are put forward. According to the design of the magneto-rheological fluid test device and the detection of the material property, the theory of the rheological property of the magneto-rheological fluid is described by the Bingham model, the Bingham double-plastic model, the Herschel-Bulkley model and the Eyring constitutive model. Through the analysis and comparison, the bigham model with less parameters and more physical meaning is selected as the basis of the theoretical model of the rheological property of the magneto-rheological fluid in the composite field. Based on the working mode of the magneto-rheological fluid, the flow-type shear model, the disk shear model and the cylinder shear model are introduced, and the cylinder shear model is selected as the mechanical model base of the experimental device. The mechanical and kinematic law of the magneto-rheological fluid in the cylinder shear model is obtained by means of the finite element analysis method, and the mechanical model of the magnetorheological fluid micro-element is obtained by the force analysis of the magnetorheological fluid micro-element in the cylindrical shear model. In the end, the shear stress and shear rate of the magnetorheological fluid in the cylinder shear model are measured, and the influence of the pre-yield interval on the detection of the magneto-rheological fluid is effectively avoided. From the angle of the compound field, the influence of the magnetic field and the temperature field on the output characteristic of the magneto-rheological fluid in the working process of the magneto-rheological fluid is theoretically analyzed, and the Bingham model, the viscosity-temperature characteristic and the Curie formula are analyzed. Based on the four aspects of the change of the magnetic field strength and the rheological property of the magneto-rheological fluid, the theoretical model of the stress output of the magneto-rheological fluid in the composite field is obtained. It is found that the effect of the temperature field on the magneto-rheological fluid is the change of the permeability of the soft magnetic particles and the viscosity of the carrier liquid in the magneto-rheological fluid, and then the magnetic field strength is changed, resulting in a change of the stress output. Based on the analysis of the cylinder shear model, the magnetic field theory and the temperature field theory, the rheological property of the magneto-rheological fluid under the complex field is developed and the simulation of the temperature field and the distribution of the magnetic field is simulated by the ansys simulation. The simulation proves that the experimental device can provide a uniform and stable magnetic field and temperature field for the detection of the shear stress of the magneto-rheological fluid and the composite experimental requirement. The effects of magnetic field and shear rate on the experimental measurement, magnetic field and temperature field are designed. The influence of temperature field and magnetic field on the process of shear operation of the magneto-rheological fluid is studied from the experimental point of view. The data analysis shows that the shear stress of the magneto-rheological fluid increases with the magnetic field and the shear rate, and decreases with the rise of the temperature field. In contrast, the effect of the rise of the magnetic field strength on the stress output is much greater than the shear rate increase. It has also been found that the larger the magnetic field strength, the more the shear stress decreases as the temperature field increases. The larger the magnetic field, the greater the influence of the temperature rise on the magnetic field. The experimental data analysis shows that the influence of the temperature field through the Curie formula and the viscosity-temperature characteristic formula is the theoretical and practical coincidence of the influence of the magnetic field and the viscosity, and the correctness of the theoretical deduction is proved. The temperature field compensation experiment is designed based on the theoretical model of the magnetic field and the temperature field. The decrease of the shear stress of the magneto-rheological fluid due to the rise of the temperature field is compensated by the increase of the magnetic field. The experimental results show that the decrease of the shear stress of the magneto-rheological fluid is reduced from 30%/100 鈩，
本文编号：2435186
[Abstract]:The magneto-rheological fluid is a new type of intelligent material, which exhibits a Newtonian liquid characteristic of low viscosity in the absence of a magnetic field. Once the magnetic field is added, the response becomes a solid or solid state in the millisecond time, which is referred to as the magneto-rheological effect. At present, a large number of magneto-rheological fluid products are generally applied to the mechanical properties of the magneto-rheological fluid, so that the mechanical property research of the magneto-rheological fluid is also an important aspect of the research of the magneto-rheological fluid. In that application of a plurality of mechanical properties of the magneto-rheological fluid, the application of the shear stress characteristic is the most widely used, and therefore, the rheological property of the magneto-rheological fluid is also concentrated. The output of the shear stress characteristic of the magneto-rheological fluid is generally influenced by the magnetic field, the temperature field, the gravity field, the shear rate, the shear stress direction, the size and shape and the dispersion condition of the magnetic conductive particles, the working time, the device structure and the material property, the surface roughness and the grain of the working surface, and the like. In which the magnetic field is a necessary factor of the magneto-rheological effect of the magneto-rheological fluid, and a large amount of mechanical energy is converted into internal energy in the actual working process of the magneto-rheological fluid so as to cause the temperature rise of the magneto-rheological fluid or the non-uniform distribution of the temperature field. Therefore, the change of the magnetic field and the temperature field is the most prominent in the influence factors of the magneto-rheological fluid, and the actual operation of the magneto-rheological fluid is generally in the environment in which the magnetic field and the temperature are coupled with each other. In this paper, the main factors that influence the output of the magneto-rheological fluid and its mechanical properties are briefly introduced, and the research progress of the shear stress characteristic of the magneto-rheological fluid and the current situation and development trend of the rheological property detection technology of the magneto-rheological fluid are summarized from the aspects of the magnetic field and the temperature field. In this paper, the advantages and disadvantages of the current rheological property theory and the detection method are analyzed and compared, and the characteristics of the magnetorheological fluid under the compound field are analyzed and compared, and the research purpose, the research method and the research significance of the present invention are put forward. According to the design of the magneto-rheological fluid test device and the detection of the material property, the theory of the rheological property of the magneto-rheological fluid is described by the Bingham model, the Bingham double-plastic model, the Herschel-Bulkley model and the Eyring constitutive model. Through the analysis and comparison, the bigham model with less parameters and more physical meaning is selected as the basis of the theoretical model of the rheological property of the magneto-rheological fluid in the composite field. Based on the working mode of the magneto-rheological fluid, the flow-type shear model, the disk shear model and the cylinder shear model are introduced, and the cylinder shear model is selected as the mechanical model base of the experimental device. The mechanical and kinematic law of the magneto-rheological fluid in the cylinder shear model is obtained by means of the finite element analysis method, and the mechanical model of the magnetorheological fluid micro-element is obtained by the force analysis of the magnetorheological fluid micro-element in the cylindrical shear model. In the end, the shear stress and shear rate of the magnetorheological fluid in the cylinder shear model are measured, and the influence of the pre-yield interval on the detection of the magneto-rheological fluid is effectively avoided. From the angle of the compound field, the influence of the magnetic field and the temperature field on the output characteristic of the magneto-rheological fluid in the working process of the magneto-rheological fluid is theoretically analyzed, and the Bingham model, the viscosity-temperature characteristic and the Curie formula are analyzed. Based on the four aspects of the change of the magnetic field strength and the rheological property of the magneto-rheological fluid, the theoretical model of the stress output of the magneto-rheological fluid in the composite field is obtained. It is found that the effect of the temperature field on the magneto-rheological fluid is the change of the permeability of the soft magnetic particles and the viscosity of the carrier liquid in the magneto-rheological fluid, and then the magnetic field strength is changed, resulting in a change of the stress output. Based on the analysis of the cylinder shear model, the magnetic field theory and the temperature field theory, the rheological property of the magneto-rheological fluid under the complex field is developed and the simulation of the temperature field and the distribution of the magnetic field is simulated by the ansys simulation. The simulation proves that the experimental device can provide a uniform and stable magnetic field and temperature field for the detection of the shear stress of the magneto-rheological fluid and the composite experimental requirement. The effects of magnetic field and shear rate on the experimental measurement, magnetic field and temperature field are designed. The influence of temperature field and magnetic field on the process of shear operation of the magneto-rheological fluid is studied from the experimental point of view. The data analysis shows that the shear stress of the magneto-rheological fluid increases with the magnetic field and the shear rate, and decreases with the rise of the temperature field. In contrast, the effect of the rise of the magnetic field strength on the stress output is much greater than the shear rate increase. It has also been found that the larger the magnetic field strength, the more the shear stress decreases as the temperature field increases. The larger the magnetic field, the greater the influence of the temperature rise on the magnetic field. The experimental data analysis shows that the influence of the temperature field through the Curie formula and the viscosity-temperature characteristic formula is the theoretical and practical coincidence of the influence of the magnetic field and the viscosity, and the correctness of the theoretical deduction is proved. The temperature field compensation experiment is designed based on the theoretical model of the magnetic field and the temperature field. The decrease of the shear stress of the magneto-rheological fluid due to the rise of the temperature field is compensated by the increase of the magnetic field. The experimental results show that the decrease of the shear stress of the magneto-rheological fluid is reduced from 30%/100 鈩，
本文编号：2435186
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