Faculty Publications
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Item Design and experimental characterization of a twin-tube MR damper for a passenger van(Springer Verlag service@springer.de, 2019) Desai, R.M.; Jamadar, M.E.H.; Kumar, H.; Joladarashi, S.; Raja Sekaran, S.C.The smart behavior of magneto-rheological (MR) fluid is used in the present work in designing, experimentally characterizing and analyzing a MR damper for automotive application using the twin-tube damper concept. A commercially available passive damper of a passenger van was tested to find the characteristic damping requirement of the vehicle. With this as reference, a twin-tube MR damper working in valve mode was designed and fabricated. The magnetic flux density induced in the fluid flow gap is maximized using Taguchi analysis and finite element method magnetics (FEMM) software. The FEMM results are validated by verifying with results obtained analytically using electromagnetic circuit theory. The MR damper filled with commercially available MR fluid was experimentally tested in damper testing machine. The results demonstrate that the force developed by the MR damper is indeed increasing with the value of the current supplied. At various frequencies of input oscillation, the energy dissipated by the MR damper in a single cycle increases significantly with current supplied. The novelty of this work is that a twin-tube MR damper working in valve mode was designed as a replacement for the passive damper used in a passenger van. The MR damper thus developed is capable of producing practical levels of damping force at actual operating frequencies and amplitudes of the passive damper in the passenger van. For further analysis, the behavior of the MR damper is modeled by using the Bouc–Wen model for hysteretic systems. A proportional–integral–derivative controller is used to track the desired damping force in time domain to demonstrate the application of the MR damper in a semi-active suspension system. © 2019, The Brazilian Society of Mechanical Sciences and Engineering.Item Evaluation of a commercial MR damper for application in semi-active suspension(Springer Nature, 2019) Desai, R.M.; Jamadar, M.E.H.; Kumar, H.; Joladarashi, S.; Rajasekaran, S.C.; Amarnath, G.As the rheology of a magneto-rheological (MR) fluid can be controlled by an externally applied magnetic field, the damping force generated by a MR damper can be controlled by varying the current supplied to an electromagnet inside the damper. This paper presents the experimental evaluation of such a MR damper RD-8040-1 by Lord Corporation, USA, and its application in a semi-active suspension. The experiments were carried out in damping force testing machine. Sinusoidal displacement input was given to the test damper. The set of experiments were repeated for different levels of current (0–1.5 A in steps of 0.25 A) supplied to the MR damper. Plots of force versus displacement for each frequency of excitation and plots of maximum force versus frequency of excitation show that higher values of current lead to elevated values of MR damper forces. This increase in MR damper load with current supplied is studied and analyzed to develop a mathematical model of the MR damper under investigation. The nonlinear softening hysteretic behavior of the MR damper is simulated by using genetic algorithm provided in the optimization toolbox of MATLAB. Calculations on energy dissipation and equivalent damping coefficient of the MR damper show that the same damper can make the suspension system behave as an underdamped system, critically damped system or overdamped system depending on the value of current supplied to it. The application of this MR damper for heavy vehicle driver’s seat suspension is explored with the help of MATLAB simulations. © 2019, Springer Nature Switzerland AG.Item Experimental and Analytical Evaluation of an Acceleration-Based Semiactive Control Strategy for Automotive Suspension Systems with Magneto-Rheological Damper(SAE International, 2023) Jamadar, M.E.H.; Devikiran, P.; Kumar, H.; Joladarshi, S.Most of the control strategies presented to date are based on either the velocities or displacement of the vehicle body and the wheel which are derived by filtering and converting the data from the accelerometer. This increases the computational load and therefore directly affects the performance of the semiactive suspension system. This study presents a control strategy purely based on the acceleration for semiactive control of vehicle suspension with a magneto-rheological MR damper. The effectiveness of the acceleration-based skyhook (ASH) control strategy is compared with the existing velocity-based skyhook (VSH) control strategy based on the vibration response of a single-degree-of-freedom (SDOF) system. The effectiveness of ASH is evaluated experimentally, and the reaction time is evaluated analytically. The experimental results revealed that the ASH reduces the peak displacement and peak acceleration of the mass under the free vibration test and also improves the settling time as compared to VSH. The amplitude of the displacement and acceleration was also found to be reduced under the forced vibration test with maximum improvement observed during high-frequency excitation. The reaction time of ASH was also found to be considerably lower than VSH. Therefore, it was learned that the proposed ASH performed better under high-frequency excitation than under lower-frequency excitation. Moreover, the lower reaction time of the ASH could improve the overall performance of the semiactive suspension system. © 2023 SAE International.Item Optimization and experimental analysis of a cost-effective magneto-rheological (MR) fluid for application in semiactive suspension of a passenger van(SAGE Publications Ltd, 2024) Jamadar, M.E.H.; Devikiran, P.; Kumar, H.; Joladarashi, S.The study presented in this article attempts to determine the optimal composition of iron particles in the MR fluid for vehicular application based on the size of the particles, the simulation response of a test vehicle model, and the cost of the fluid. The MRF samples with two different-sized particles in varying compositions are prepared and characterized on a rheometer. The performance of each MRF sample in the semiactive suspension of a test vehicle is determined by simulating its full car model on a random road. The response of the vehicle model during simulation, the size of the particles, the volume fraction of the particles in the carrier fluid, and the fluid’s calculated cost are input for the Response surface optimization technique. The optimization results revealed that the MR fluid with large-sized particles in a 25% volume fraction would be suitable for the said application. Moreover, it was found that the rheological performance of the optimized MR fluid was better than the commercial MR fluid. The performance of the optimized fluid in a MR damper was experimentally evaluated against the stock passive damper of the test vehicle. The results of the experiment on the test vehicle showed that the MR damper improved the test vehicle’s ride comfort by 36.58% over a speed bump and 11.3% on an off-road test track. The road handling was also improved by 45% over a speed bump and 46% over the test track. © IMechE 2023.