The Field Of Rheology Rheological Properties And Testing Technology

Field fluids included electrorheological fluid and magnetorheological fluid, an important branch of intelligent materials, attracted more and more attention by industry and technology with its electromechanical coupling characteristics. Under the effects of electric or magnetic field, its apparent shear viscosity and yield stress can occur rapidly, controllable, continuous and reversible changes. Mechanism studies and engineering applications of field fluids are dependent on experimental data. At present, the testing equipment for field fluids is still lacking, therefore available experimental data is far from perfect.From the view of application,this paper studies on rheological properties and mechanical vibration characteristics of electrorheological fluid.The specific research topics are:Experimental study of rheology of electrorheological fluid under shear state.The rheology characteristics of electrorheological fluid under steady flow and oscillatory flow was performed.For the steady shear flow,the effect to the dynamic yield stress and apparent viscosity caused by the field strength,shear rate,quality fraction was experimentally studied.For the oscillatory flow, the changes of shear modulus under different stress amplitude and frequency were tested,the effect factors of viscoelastic properties of electrorheological fluid were studied and the changed rules of storage modulus,loss modulus and loss factor with amplitude and frequency were received.The design of the wavered test device of the field fluid.Due to the complex fluid rheological properties,there is a lack of testing equipment for the experimental study.In this paper,using vibration testing principle,a test device for field fluid was designed,the affecting factors device was analyzed and the dynamic propertiesof the test device was measured.Research on vibration response of mechanical characteristics of change damping of electrorheological fluid. An experimental study on electrorheological fluid under sinusoidal excitation using test system composed by self-designed test equipment, and provided a new method of testing new materials with complex properties and hard test.Through the analysis of vibration of electrorheological fluid, in order to better grasp response relationship of ERF under a given voltage and frequency of the exciting force,a simplified mechanical model of variable parameters is putted out by means of equivalent displacement.