Magnetorheological fluid

About: Magnetorheological fluid is a research topic. Over the lifetime, 8538 publications have been published within this topic receiving 131502 citations. The topic is also known as: MRF & MR fluid.

Volume-constrained optimization of magnetorheological and electrorheological valves and dampers

Abstract: This paper presents a case study of magnetorheological (MR) and electrorheological (ER) valve design within a constrained cylindrical volume. The primary purpose of this study is to establish general design guidelines for volume-constrained MR valves. Additionally, this study compares the performance of volume-constrained MR valves against similarly constrained ER valves. Starting from basic design guidelines for an MR valve, a method for constructing candidate volume-constrained valve geometries is presented. A magnetic FEM program is then used to evaluate the magnetic properties of the candidate valves. An optimized MR valve is chosen by evaluating non-dimensional parameters describing the candidate valves' damping performance. A derivation of the non-dimensional damping coefficient for valves with both active and passive volumes is presented to allow comparison of valves with differing proportions of active and passive volumes. The performance of the optimized MR valve is then compared to that of a geometrically similar ER valve using both analytical and numerical techniques. An analytical equation relating the damping performances of geometrically similar MR and ER valves in as a function of fluid yield stresses and relative active fluid volume, and numerical calculations are provided to calculate each valve's damping performance and to validate the analytical calculations.

Modelling the hysteresis phenomenon of magnetorheological dampers

Abstract: Recently, magnetorheological (MR) dampers have emerged as a potential technology to implement semi-active control in structures and vehicle applications in order to efficiently suppress vibration Perfect understanding about the dynamic characteristics of such dampers is necessary when implementing MR struts in application One of the important factors to successfully attain desirable control performance is to have a damping force model which can accurately capture the inherent hysteresis behavior of MR dampers Different models have been proposed to simulate the hysteresis phenomenon in such a kind of damper The Bouc–Wen model has been extensively used to simulate the hysteresis behavior of MR dampers However, considerable differences still exist between the simulation and experimental results In this work, a methodology to find the characteristic parameters of the Bouc–Wen model in the attempt to better characterize the hysteresis phenomenon of MR dampers has been proposed The methodology takes into consideration the effect of each individual term of the Bouc–Wen model over the hysteretic loop to estimate the appropriate values of the parameters The Bouc–Wen model in which the new established characteristic parameters have been used has been validated against experimental data and an excellent agreement has been shown between the simulation and experimental results Moreover, the findings pointed towards the fact that linear or exponential relationships exist between the estimated parameters and the current excitation Considering this, a new model based on the Bouc–Wen model has been proposed in which the excitation current has been incorporated as a variable This proposed modified Bouc–Wen model has also been validated against the experimental results and a good correlation has been found

Magnetorheological dampers in shear?mode

Abstract: In this study, three types of shear mode damper using magnetorheological (MR) fluids are theoretically analyzed: linear, rotary drum, and rotary disk dampers The damping performance of these shear mode MR dampers is characterized in terms of the damping coefficient, which is the ratio of the equivalent viscous damping at field-on status to the damping at field-off status For these three types of shear mode MR damper, the damping coefficient or dynamic range is derived using three different constitutive models: the Bingham–plastic, biviscous, and Herschel–Bulkley models The impact of constitutive behavior on shear mode MR dampers is theoretically presented and compared