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.

Self-Powered Magnetorheological Dampers

Abstract: This study addresses the feasibility and effectiveness of a self-powered magnetorheological (MR) damper using in-situ energy harvested from the vibration and shock environment in which it is deployed. To achieve this, an energy-harvesting device is designed and added to a MR damper. This energy-harvesting device consists of a stator, a permanent magnet, and a spring and operates as an energy-harvesting dynamic vibration absorber (DVA). The dynamic equation for the self-powered MR damper is derived. To evaluate the vibration isolation capability of the self-powered MR damper, a single-degree-of-freedom engine mount system using the MR damper is simulated. The governing equation of motion for the engine mount system is derived. A parametric study is conducted to find the optimal stiffness of the energy-harvesting DVA for the engine mount system. The isolation performance of the engine mount system employing the self-powered MR damper is theoretically evaluated in the frequency domain.

Characterization and Analysis of Magnetorheological Damper Behavior Under Sinusoidal Loading

Abstract: The hysteresis behavior of a linear stroke magnetorheological damper is characterized for several magnetic fields and sinusoidal excitations over a nominal operational frequency range of 10-30 Hz The behavior of the damper is inadequately modeled using the equivalent viscous damping and the complex modulus Therefore, four different nonlinear modeling perspectives are discussed for purposes of system identification procedures, including the 1) nonlinear Bingham plastic model, 2) nonlinear biviscous model, 3) nonlinear hysteretic biviscous model, and 4) nonlinear viscoelastic plastic model The first three nonlinear models are piecewise continuous in velocity The fourth model is piecewise smooth in velocity The parameters for each model are identified from an identification set of experimental data; these parameters are then used to reconstruct the force vs displacement and the force vs velocity hysteresis cycles for the respective model Model performance is evaluated by calculating equivalent viscous damping and force time history errors between the model fit and the experimental data In addition to the identification study, a validation study was done Model parameters were calculated for offset values of current and frequency These intermediate parameters were used to calculate hysteresis cycles, which were compared with a second set of experimental data, a validation data set Identification and validation study results including damping levels and force time history errors

A study of the magnetorheological effect of bimodal particle based magnetorheological elastomers

Abstract: This paper presents theoretical and experimental studies of the mechanical performance and magnetorheological effects of magnetorheological elastomers (MREs) fabricated with mixtures of large and small particles. First of all, an effective permeability model was developed to theoretically analyze the MR effect of bimodal particle based MR elastomers. From the theoretical analysis, an optimum volume fraction was derived which resulted in enhanced MR effects. Two categories of iron products with different particle sizes of 50 and 5? ?m were used to fabricate a series of bimodal MRE samples. Their mechanical performances were characterized by using an MR rheometer. Experimental results agreed fairly well with theoretical analysis. The theoretical prediction of the optimum mixture ratio between large and small size particles was experimentally verified.