Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
8 results
Search Results
Item Analyzing quarter car model with Magneto-Rheological (MR) damper using equivalent damping and Magic formula models(Elsevier Ltd, 2019) Jamadar, M.-E.-H.; Desai, R.M.; Kumar, H.; Joladarashi, S.Mathematical modelling of Magneto-Rheological (MR) damper has been an intriguing field of research ever since the invention of the device itself. An accurate model of MR damper results in development of an efficient controller for a semi-active system with MR damper. Hence, a number of models have been put forward to accurately predict the MR damper behavior. One of these models is Magic formula model. Based on the famous Magic formula used in tire force calculation, this model can be used for representing the peak damper force vs damper piston velocity amplitude graph. This model was later modified to capture the force displacement diagram of MR damper. The former model is denoted as Magic Formula Model-1 (MFM-1) and the latter one is denoted as Magic Formula Model-2 (MFM-2) here onwards. In the current study a commercial MR damper has been tested for various piston velocities and currents. The equivalent damping coefficient is then calculated for the tested conditions. The equivalent damping coefficients are used for analyzing a quarter car model. Two quarter car models with MR damper are simulated, one uses MFM-1 for MR damper and the other uses MFM-2. All the quarter car models are subjected to single pulse input and the sprung mass response is measured in terms of displacement. The RMS error between the response of quarter car model with equivalent damping and quarter car models with MR damper is used to determine the performance of each mathematical model. The study revealed that MFM-1 represents the MR damper behavior more accurate than that of MFM-2. © 2019 Elsevier Ltd.Item Experimental investigation and mathematical modeling of automotive passive damper for SUV suspension system(American Institute of Physics Inc. subs@aip.org, 2020) Desai, R.M.; Jamadar, M.-E.-H.; Kumar, H.; Joladarashi, S.Dampers are energy dissipating devices used along with energy absorbing devices like coil springs to form the major parts of an automobile suspension system. They provide the passengers of the vehicle the desired comfort and the vehicle the necessary stability and road holding. In the present work, a viscous damper of twin tube design working in the passive mode is evaluated on a damper testing machine and its performance is characterized. Its behavior at different velocities and frequencies of excitation is studied. Using the dissipated energy method, the equivalent damping coefficient of the damper is calculated for different frequencies of excitation. Mathematical models are developed for the force vs velocity behavior of the damper as the damper force is a function of the damper piston velocity. These mathematical models based on the experimental results will be very much useful in designing an alternative or improved suspension system for the vehicle under consideration. © 2020 Author(s).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 Dynamic Analysis of a Quarter Car Model with Semi-Active Seat Suspension Using a Novel Model for Magneto-Rheological (MR) Damper(Springer, 2021) Jamadar, M.-E.-H.; Desai, R.M.; Saini, R.S.T.; Kumar, H.; Joladarashi, S.Mathematical modeling of magneto-rheological damper has been an intriguing field of research ever since the invention of the device itself. An accurate magneto-rheological damper model results in development of an efficient current controller in a semi-active seat suspension system featuring magneto-rheological damper. Hence, a number of models have been put forward to accurately predict the magneto-rheological damper behavior. This paper presents another mathematical model for magneto-rheological dampers based on their equivalent damping. A commercially available magneto-rheological damper has been used for characterization in this study. The magneto-rheological damper behavior is characterized using two models, Bingham model and equivalent damping model. These models are then used to simulate the magneto-rheological damper in a quarter car model with four degree of freedom featuring semi-active seat suspension that is subjected to bump road input and random road input. The magneto-rheological damper model is supplied with current using two control logics, on–off Skyhook logic and Proportional Integral and Differential logic. The performance of the two models are compared based on driver mass response in each case of seat suspension model and computation time. The results show that equivalent damping model can represent the magneto-rheological damper behavior with sufficient accuracy while reducing computational time by 30% irrespective of type of road input or type of control logic implemented. The reduced computational time is an added advantage when magneto-rheological damper is used in real-time. © 2020, Krishtel eMaging Solutions Private Limited.Item Performance Evaluation of a Single Sensor Control Scheme Using a Twin-Tube MR Damper Based Semi-active Suspension(Springer, 2021) Desai, R.M.; Jamadar, M.-E.-H.; Kumar, H.; Joladarashi, S.Background: Magneto-rheological (MR) dampers have a promising future for application in automotive semi-active suspensions. The damping force produced by MR dampers can be modulated by controlling the electric current supplied to it. Purpose: The present work explores a twin-tube MR damper working in valve mode for application in a semi-active SUV suspension system. Further, the performance of a single sensor control scheme is evaluated. Methods: The MR damper is characterized in a damper testing machine to demonstrate the MR behaviour and also to show that it develops similar magnitude of force as a passive damper used in SUV suspension. To prove the superiority of semi-active suspension, a single degree of freedom quarter car test rig is built and ground excitation is given in the form of displacement input from a hydraulic actuator. Constant current control, Skyhook control and Rakheja-Sankar (RS) control method are employed as three different control strategies and compared with passive suspension to study the advantages. Peak acceleration response of the sprung mass is studied for better passenger ride comfort and peak ground force is studied for preventing damage to road surface as well as to vehicle suspension elements. Results: RS control provides much lower sprung mass vertical acceleration than Skyhook control and constant current control. RS control method led to 36% reduction of peak ground force when compared to Skyhook control. Conclusion: For a semi-active suspension using twin-tube MR damper, RS control method provides better ride comfort to passengers due to lower peak vertical acceleration when compared to constant current control or Skyhook control method. Moreover, for preventing damage to road surface as well as to vehicle suspension elements, RS control method, requiring a single sensor, is a much better choice. © 2021, Krishtel eMaging Solutions Private Limited.Item Real-time testing and thermal characterization of a cost-effective magneto-rheological (MR) damper for four-wheeler application(Springer Science and Business Media Deutschland GmbH, 2023) Jamadar, M.E.H.; Devikiran, P.; Desai, R.M.; Kumar, H.; Joladarashi, S.Recent studies show that the Magento-Rheological (MR) dampers can serve as a suitable replacement for passive dampers on ground vehicles. MR dampers are factory fitted in premium luxury vehicles. However, the high price of these MR dampers has restricted their use to premium vehicles only. The study presented in this article attempts to develop a MR damper, in collaboration with a shock absorber manufacturer, that can replace the existing passive dampers on a passenger van while being more affordable than the commercially available MR dampers. The developed MR damper is subjected to rigorous testing on the damper testing machine to evaluate its damping performance, reliability and thermal performance. The simulation results of the test vehicle model revealed a superior MR damper performance compared to the stock passive damper. The MR damper is later installed on the test vehicle to conduct real-time experiments. The real-time experiments showed that the developed MR damper improved the ride comfort of the test vehicle by 16.2% at 10 km/hr and by 17.6% at 20 km/hr compared to passive dampers while running over a speed bump. The road handling also improved by 14.32% at 10 km/hr and by 29.3% at 20 km/hr. At the end of the study, the cost evaluation performed on the developed MR damper revealed that it was more affordable than the commercially available MR dampers. © 2023, The Author(s), under exclusive licence to The Brazilian Society of Mechanical Sciences and Engineering.Item Synthesis, characterization and selection of optimal constituents of magnetorheological fluid for damper application(National Institute of Science Communication and Policy Research, 2025) Acharya, S.; Puneet, N.P.; Desai, R.M.; Sundaram, V.; Kumar, H.Magnetorheological (MR) dampers are a category of energy dissipating devices that employ magnetorheological fluids which undergoes drastic change in its behaviour under the presence of magnetic stimulus. The damping characteristics of an MR damper predominantly depends on the dimensions of damper and on the constituents of MR fluid (MRF). In this work, an optimal MRF composition suitable for a monotube MR damper has been selected from six prepared MRF based on optimization. Initially, MR damper piston dimensions have been obtained by means of optimization. The damper has been fabricated and filled with commercial MRF 132DG™ fluid (Lord Corporation) and its performance has been tested. The experimental results have been validated with computational results. In the next part of the study, MRF samples composed of three particle weight fractions of fine and coarse sized iron particles have been synthesized and the rheological properties have been measured and compared with those of commercial MR fluid. The force-displacement characteristics of damper employing synthesized MRF have been determined with and without application of current to damper coil. Finally, by means of Multi-Objective Genetic Algorithm, optimum iron particle size and weight fraction have been selected from the pareto front solutions. © 2025, National Institute of Science Communication and Policy Research. All rights reserved.