Magnetorheological fluid settleability testing device and testing method

Abstract

The invention provides a magnetorheological fluid settleability testing device and testing method. The device includes a uniform constant magnetic field generating device, a magnetorheological fluid container arranged in the effective output area of the uniform constant magnetic field generating device, multiple pairs of conducting strips arranged at different heights in the magnetorheological fluid container, and ohmmeters for measuring resistance between each pair of the conducting strips. Under same magnetic field intensity, the rheological effect of a magnetorheological fluid can make magnetic particles arranged according to a magnetic field direction, so that a chain type structure can be formed, and the magnetorheological fluid can have a certain conductivity by utilizing the chain type structure; and through the utilization of the characteristic that resistance reduces with the increasing of particle concentrations, the method of characterizing a magnetorheological fluid settlement process by comparing situations of the change of the resistance of the magnetorheological fluid at different positions with time can be designed, and therefore, ideal technical schemes for evaluating the settlement performance of magnetorheological fluid materials can be obtained.

Description

technical field [0001] The invention relates to the field of material performance testing, in particular to a magnetorheological fluid sedimentation test device and a test method. Background technique [0002] Magnetorheological fluid is generally composed of non-magnetic carrier fluid, micron-sized particles with high magnetic permeability and low hysteresis (commonly used carbonyl iron powder), and functional additives for improving certain properties. In the state where no magnetic field is applied, the magnetorheological fluid exhibits low-viscosity Newtonian fluid characteristics, and the particles are uniformly dispersed in the carrier fluid. When a certain strength of magnetic field is applied, the ferromagnetic particles are magnetized to form magnetic dipoles and obtain magnetic dipole moment. Certain shear resistance and conductivity, when the external magnetic field is removed, the magnetorheological fluid returns to a static state. This characteristic of magnet...

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Problems solved by technology

The visual method can obtain the relationship between the displacement of the mudline and time, and calculate the sedimentation rate of the mudline at each initial concentration, but this method can only monitor the settlement process of the transparent magnetorheological fluid, and cannot directly obtain the settlement of all areas below the mudline information, and the measurement is time-consuming and the error is large

The inductance method uses the magnetic permeability of the magnetorheological fluid to decrease with the decrease of the particle volume, so that the inductance of the solenoid inductance coil surrounding the liquid decreases accordingly. The movement error of the sensor monitoring position is large, and the sensitivity of the inductance tester is high.

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