Device and method for testing high-shear rate rheological behavior of magnetorheological fluid

Abstract

The invention provides a device and a method for testing the high-shear rate rheological behavior of a magnetorheological fluid. The device comprises a cylindrical housing, wherein the upper end and the lower end of the housing are respectively provided with an upper end cover and a lower end cover; the housing is internally provided with a piston, the housing is internally divided into an upper cavity and a lower cavity, the piston is inverted barrel-shaped, the bottom surface of the piston is opened, and the top surface of the piston is provided with a normal through hole; a piston rod is arranged in the piston in a penetrating manner, and the piston rod is arranged in the upper end cover in the penetrating manner to the outer part of the housing; a part of the position rod, arranged in the piston, is provided with a magnetic core in a winding way, the upper part of the magnetic core is provided with a coil in a winding way, and the coil is electrically connected with the outside through a conducting wire; the diameter of the lower cross section of the magnetic core is slightly less than the lower inner diameter of the piston to form a ring-shaped damp gap; the upper part of the upper cavity is provided with an upper oil pressure sensor, and the lower part of the lower cavity is provided with a lower oil pressure sensor; and the housing is internally provided with a temperature sensor. According to the device and the method, the influence of friction force on a test result can be removed, the influence of temperature factors can be sufficiently considered, and the device and the method have the advantages of being high in shear rate and exact in result.

Description

technical field [0001] The invention belongs to the technical field of testing the rheological properties of magnetorheological fluids, in particular to a testing device and a testing method for high shear rate rheological properties of magnetorheological fluids. Background technique [0002] Magnetorheological fluid is one of the smart materials with the most intensive research and the fastest progress at present, and it involves many fields such as vehicle suspension, brakes, weapon systems, and civil engineering structures. For applications in different fields, the flow velocity and shear rate of magnetorheological fluids are very different. For example, tanks, heavy-duty off-road vehicle suspension systems, and artillery barrel recoil damping systems, under impact loads, the flow rate of magnetorheological fluid is high, and the shear rate can exceed 10 5 the s -1 . Under such extreme conditions, MR fluids may behave differently than under low flow, low shear rate con...

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Problems solved by technology

[0004] However, the magnetorheological fluid detection device based on the shear working mode has the following problems: 1) Due to problems such as end effect and wall slip effect, the highest shear rate of this type of rheological test device is less than 10 3 the s -1 , which cannot be used to test the rheological properties at high shear rates; 2) The shear rate of the magnetorheological fluid in the damping gap is nonlinear in the velocity profile, and this nonlinearity increases with the increase of the flow rate, however In order to simplify the calculation process, the existing detection methods often linearize it, resulting in a large difference between the test results and the actual ones. Therefore, there are very few studies on the rheological characteristics of magnetorheological fluids under extreme conditions of high shear rate. One of the reasons is the lack of corresponding rheological properties testing experimental equipment; 3) It is difficult to rule out the influence of friction on the results; 4) It is difficult to determine the influence of temperature on the performance of magnetorheological fluids

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