scholarly journals Multiphysics Analysis of a Magnetorheological Damper

2019 ◽  
Vol 69 (3) ◽  
pp. 230-235 ◽  
Author(s):  
A. J. D. Nanthakumar ◽  
J. Jancirani ◽  
S. C. Rajasekaran ◽  
K. Sarathkumar

     A Magnetorheological damping has evolved as a potential tool in vibration control. The design of magnetorheological damping involves analysis of fluid flow principles and electromagnetic flux analysis. This research paper involves design and analysis of a magnetorheological damper employed for vibration control. The analysis is carried over by considering the domain as an axisymmetric model. The damping force of the damper depends upon the shear stress due to fluid viscosity and yield stress induced due to magnetic flux applied. The damping force generated by the damper is calculated.

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Zhizhen Dong ◽  
Zhimin Feng ◽  
Yuehua Chen ◽  
Kefan Yu ◽  
Gang Zhang

The consistency of magnetic flux density of damping gap (CMDG) represents the balancing magnetic flux density in each damping gap of magnetorheological (MR) dampers. It can make influences on the performances of MR dampers and the accuracy of relevant objective functions. In order to improve the mechanical performances of the MR damper with a two-stage coil, the function for calculating CMDG needs to be found. By establishing an equivalent magnetic circuit model of the MR damper, the CMDG function is derived. Then, the multiobjective optimization function and the working flow of optimal design are presented by combining the parallel-plate model of the MR damper with the function posed before. Taking the damping force, the dynamic range, the response time, and the CMDG as the optimization objective, and the external geometric dimensions of the SG-MRD60 damper as the bound variable, this paper optimizes the internal geometric dimensions of MR damper by using a NSGA-III algorithm on the PlatEMO platform. The results show that the obtained scheme in Pareto-optimal solutions has existed with better performance than that of SG-MRD60 scheme. According to the results of the finite element analysis, the multiobjective optimization design including the CMDG function can improve the uniformity of magnetic flux density of the MR damper in damping gap, which meets the requirements of manufacture and application.


Author(s):  
Ahmad Zaifazlin Zainordin ◽  
Gigih Priyandoko ◽  
Zamri Mohamed

Magnetorheological (MR) damper as a semi-active system for a vehicle suspension is simulated in this study. The proposed design of Magnetorheological (MR) valve consists of meandering flow channel or gaps that fixed in the piston of the damper. The focus of this study is to estimate the performance of proposed MR valve based on actual front suspension parameter of a vehicle. Annular and radial gaps are combined to produce an MR valve with meandering fluid flow path. Furthermore, the damper is filled with Magnetorheological (MR) fluid to energize the damper under the presence of magnetic fields. The magnetic flux density within each gap is obtained via the Finite Element Method Magnetics (FEMM) software. Therefore, the yield stress of MR fluid and magnetic flux relationships both can be predicted. The present paper shows a reduction in pressure drop when the thickness of each gap is increased. Pressure drop is closely affected by the fluid flow rate that enters each gap. This means that the lower flow rate increases the pressure drop of MR valve at various current.


Author(s):  
Muhammad Adhar Bagus ◽  
Azizan As’arry ◽  
Hesham Ahmed Abdul Mutaleb Abas ◽  
Abdul Aziz Hairuddin ◽  
Mohd Khair Hassan

Recently MRF damper -which has a significant controllable damping force - used frequently in many active and semi-active suspension systems. However, MRF damper needs controller to estimate the desired force to dissipate the occurred vibration instantaneously. PID controller is one of the effective feedback controllers which shows robustness and simplicity in control MRF dampers, but still the parameters of the PID controller under study to find out the optimum values. This study focused on the vibration control using Magneto-rheological (MR) damper on a FSAE quarter car suspension test rig to study and obtain the optimum running condition. The test rig was designed, modified and then tested using a P-controller integrated with MR damper, unbalance mass used as disturbance and analyzed using LABVIEW software in time and frequency domains. The natural frequency obtained was 2.2 Hz were similar to the actual FSAE car natural frequency. Based on the acceleration against time graph with different proportional gain value the optimal value for proportional gain, Kp was 1. Hence, the experiment work could be used as the initial stage to study and develop a robust controller to suppress vibration on a car.


2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Sy Dung Nguyen ◽  
Dongsoo Jung ◽  
Seung-Bok Choi

This work proposes a novel adaptive type 2 fuzzy sliding controller (AT2FC) for vibration control of magnetorheological damper- (MRD-) based railway suspensions subjected to uncertainty and disturbance (UAD). The AT2FC is constituted of four main parts. The first one is a sliding mode controller (SMC) for specifying the main damping force supporting the suspension. This controller is designed via Lyapunov stability theory. The second one is an interpolation model based on an interval type 2 fuzzy logic system for determination of optimal parameters of the SMC. The third one is a nonlinear UAD observer to compensate for external disturbances. The fourth one is an inverse MRD model (T2F-I-MRD) for specifying the input current. In the operating process, an adaptively optimal structure deriving from the SMC is created (called the Ad-op-SMC) to adapt to the real status. Working as an actuator, the input current for MRD is then determined by the T2F-I-MRD to generate the required damping force which is estimated by the Ad-op-SMC and the nonlinear observer. It is shown that the obtained survey results reflect the AT2FC’s excellent vibration control performance compared with the other controllers.


2017 ◽  
Vol 36 (2) ◽  
pp. 177-192 ◽  
Author(s):  
Raju Ahamed ◽  
MM Rashid ◽  
MM Ferdaus ◽  
Hazlina B Yusuf

In this study, an magnetorheological (MR) damper has been designed based on its energy harvesting capability which combines the key benefits of energy generation (reusing lost energy) and magnetorheological damping (controllable damping force). The energy harvesting part has a magnet and coil arrangement to generate energy. A two-dimensional axisymmetric model of the proposed magnetorheological damper is developed in COMSOL Multiphysics where different magnetic field properties are analysed generally by finite element method. Finally, the energy harvesting capability of the proposed magnetorheological damper model is tested by a universal testing machine and observed through an oscilloscope. The maximum induced output voltage was around 0.7 V.


2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Xin De-kui ◽  
Nie Song-lin ◽  
Ji Hui ◽  
Yin Fang-long

Magnetorheological fluid (MRF) damper is one of the most promising semiactive devices for vibration control. In this paper, a shear-valve mode MRF damper for pipeline vibration control is proposed. The dynamic model and the state equation of the pipeline are established and the linear quadratic regulator (LQR) is used to generate the optimal damping force of MRF damper. The design concept considering the structure and the electromagnetic properties simultaneously is discussed in detail. A mathematical model of the relation between shear stress and control current based on interpolation method is established. Finite element analysis (FEA) software COMSOL is selected to simulate the magnetic field and electromagnetism-thermal field of the MRF damper. A computational method based on the simulation model is established to calculate the shear stress. In order to reduce the magnetic leakage, a method of adding magnetism-insulators at both ends of the piston head is presented. The influence of control current, displacement, and velocity on mechanical performance of the proposed MRF damper is experimentally investigated. The test results show that the performance of the MRF damper is basically identical with the theoretical prospective and the simulation conclusions, which proves the correctness and feasibility of this design concept.


2018 ◽  
Vol 21 (1) ◽  
pp. 02-14 ◽  
Author(s):  
Phu Xuan Do ◽  
Long Bui Quoc Mai ◽  
Chi Van Le ◽  
Thang Le Huy Tran

In this study, a new development of knee exoskeleton is presented. Kinematic parameters of the proposed exoskeleton are analysed to find relations among forces and torques. After analysing, the damping force of magneto-rheological (MR in short) damper is carried out. The magnetic flux density and the yield stress functions are found, and these functions are bases for derivation of damping force formulation. The forces from the exoskeleton are directly related to the damping force. Hence these values are used as an objective to find the optimized geometry of the damper. The optimization process is done by using ANSYS ADPL. It is shown that the requirement of design is obtained.


2018 ◽  
Vol 180 ◽  
pp. 02091
Author(s):  
Dominik Šedivý ◽  
Petr Ferfecki ◽  
Simona Fialová

This article presents the evaluation of force effects on squeeze film damper rotor. The rotor is placed eccentrically and its motion is translate-circular. The amplitude of rotor motion is smaller than its initial eccentricity. The force effects are calculated from pressure and viscous forces which were measured by using computational modeling. Damper was filled with magnetorheological fluid. Viscosity of this non-Newtonian fluid is given using Bingham rheology model. Yield stress is not constant and it is a function of magnetic induction which is described by many variables. The most important variables of magnetic induction are electric current and gap width between rotor and stator. The simulations were made in finite volume method based solver. The motion of the inner ring of squeeze film damper was carried out by dynamic mesh. Numerical solution was solved for five different initial eccentricities and angular velocities of rotor motion.


Author(s):  
Yi Shi ◽  
Jianjun Zhu ◽  
Haoyu Wang ◽  
Haiwen Zhu ◽  
Jiecheng Zhang ◽  
...  

Assembled in series with multistage, Electrical Submersible Pumps (ESP) are widely used in offshore petroleum production due to the high production rate and efficiency. The hydraulic performance of ESPs is subjected to the fluid viscosity. High oil viscosity leads to the degradation of ESP boosting pressure compared to the catalog curves under water flow. In this paper, the influence of fluid viscosity on the performance of a 14-stage radial-type ESP under varying operational conditions, e.g. rotational speeds 1800–3500 r/min, viscosities 25–520 cP, was investigated. Numerical simulations were conducted on the same ESP model using a commercial Computational Fluid Dynamics (CFD) software. The simulated average pump head is comparable to the corresponding experimental data under different viscosities and rotational speeds with less than ±20% prediction error. A mechanistic model accounting for the viscosity effect on ESP boosting pressure is proposed based on the Euler head in a centrifugal pump. A conceptual best-match flowrate QBM is introduced, at which the impeller outlet flow direction matches the designed flow direction. The recirculation losses caused by the mismatch of velocity triangles and other head losses resulted from the flow direction change, friction loss and leakage flow etc., are included in the model. The comparison of model predicted pump head versus experimental measurements under viscous fluid flow conditions demonstrates good agreement. The overall prediction error is less than ±10%.


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