The Research On Magnetorheological Fluid Rheological Properties Under The Non-uniform Magnetic Field

Magnetorheological fluid is mainly composed of ferromagnetic particles, liquid andadditive. When Magnetorheological fluid is in the case of an external magnetic field, it caninstantaneously convert from Newtonian liquid to a solid-like rigidity with high viscosity. Atthe moment, the anti-shear ability of magnetorheological fluid is rapidly increasing, and it canbe adjusted real timely with the changes in the external magnetic field; when the externalmagnetic field is removed, the magnetorheological fluid will instantly show properties ofNewtonian liquid. The changes are rapid and reversible.At present, most of the magnetorheological fluid researches are mainly concentrated inthe uniform magnetic field; researches on non-uniform magnetic field are less. In practice, theuniformity of the magnetic field is always difficult to be guaranteed, thus the changes ofmagnetic field will affect the components normal work of the magnetorheological fluid,which will result in component failure when seriously. Therefore, this paper is a research onthe characteristics of magnetorheological fluid under the perspective of non-uniform magneticfield.The rheological properties of magnetorheological fluid mainly refer to the ability ofresistance to deformation under magnetic field and it mainly presented by the shearcharacteristics. Based on the researches of the shear properties of magnetorheological fluidunder the uniform magnetic field, this paper focuses on the study of the shear properties ofmagnetorheological fluid under the non-uniform magnetic field; the main work is as follows:(1) According to the basic principle of magnetorheological phenomenon, this paper takesadvantages of the theory of magnetic dipole to analyze the micro force of magnetorheologicalfluid particles and establishes the ionic polarization model of magnetorheological fluidparticle forces under the uniform magnetic field; It also complete the theory model deductionof the magnetorheological fluid shear stress and analyze why magnetic field distribution is notuniform and put forward the corresponding shear stress model.(2) This paper builds the shear properties devices of magnetorheological fluid undernon-uniform magnetic field. The device is mainly composed of non-uniform magnetic fieldgenerating device, cutting device and data acquisition. This paper completes the constructionof non-uniform magnetic field by using the method of double electromagnet field andconducts the analysis of the electromagnet calculation. This paper also sets the shear directionof sheer device according to magnetic field simulation and selects the measurement modelthrough rational analysis.(3) Taking the advantages of the superposition principle of magnetic field, it analyzesspatial distribution of magnetic field generating device and establishes the distribution model of the size magnetic field in shear zone. Through the study of spatial distribution of themagnetic field under the effect of single electromagnet alone and the experimentalmeasurements and analysis of coupling effect under double electromagnet field, the spatialdistribution of the model is verified.(4) After the detection of the shear displacement by detecting device constructed in thispaper, shearing force of magnetorheological fluid can be received indirectly. By comparingthe shear stress measured curve and the theoretical model curve, we can conclude that theoverall trend is consistent but there are some differences. The measurement device and itsaccuracy were verified by analyzing the reasons of the differences and setting theexperiments.The main content of this paper has certain directive significance on the development ofmagnetorheological component and on the analysis of magnetorheological component failurein practical engineering application.