Experimental Investigation on Vibration Damping Characteristics of Magnetorheological Damper

Author(s):  
Ming Cheng ◽  
Zhaobo Chen ◽  
S. Nima Mahmoodi

This paper studies the vibration damping characteristics of a magnetorheological (MR) damper. A single-degree-of-freedom vibration isolation system with pedestal motion containing MR dampers has been experimentally investigated. Results show that the transmissibility at the resonance frequency does not constantly decrease as expected. It gradually decreases at the beginning, then increase unexpectedly as the input current increases. In addition, the resonant frequency of the system increases continuously. In order to explore the mechanism behind the experimental phenomenon, a centralized parameterized model of the MR damper is established. Hardening coefficient, a parameter that characterizes the dynamic characteristics of the MR damper is introduced, and the influence of the structural parameters and dynamic parameters of the MR damper on the hardening coefficient is analyzed. Simultaneously, a dynamic model of the MR damper is derived based on the Bingham model, and the damping characteristics of the MR damper are predicted and compared with the experimental results. Further, based on a simplified and equivalent dynamic model of the system, the relationship between transmissibility of the system and load mass, stiffness, and damping reveals the physical laws behind the experimental phenomenon. Finally, theoretical results are derived and compared with the experimental results, which demonstrates the rationality of the theoretical analysis.

2017 ◽  
Vol 24 (15) ◽  
pp. 3434-3453 ◽  
Author(s):  
MJL Boada ◽  
BL Boada ◽  
V Diaz

Semi-active suspensions based on magnetorheological (MR) dampers are receiving significant attention, especially for control of vibration isolation systems. The nonlinear hysteretic behavior of MR dampers can cause serious problems in controlled systems, such as instability and loss of robustness. Most of the developed controllers determine the desired damping forces which should be produced by the MR damper. Nevertheless, the MR damper behavior can only be controlled in terms of the applied current (or voltage). In addition to this, it is necessary to develop an adequate inverse dynamic model in order to calculate the command current (or voltage) for the MR damper to generate the desired forces as close as possible to the optimal ones. Due to MR dampers being highly nonlinear devices, the inverse dynamics model is difficult to obtain. In this paper, a novel inverse MR damper model based on a network inversion is presented to estimate the necessary current (or voltage) such that the desired force is exerted by the MR damper. The proposed inverse model is validated by carrying out experimental tests. In addition, a comparison of simulated tests with other damper controllers is also presented. Results show the effectiveness of the network inversion for inverse modeling of an MR damper. Thus, the proposed inverse model can act as a damper controller to generate the command current (or voltage) to track the desired damping force.


Author(s):  
S. Siva Kumar ◽  
K.S. Raj Kumar ◽  
Navaneet Kumar

Magnetorheological (MR) fluid damper has been designed, fabricated and tested to find the stiffness and damping characteristics. Experimentally the MR damper has been tested to analyse the behaviour of MR fluid as well as to obtain the stiffness for varying magnetic field. MR damper mathematical model has been developed for evaluating dynamic response for experimentally obtained parameters. The experimental results show that the increase of applied electric current in the MR damper, the damping force will increase remarkably up to the saturation value of current. The numerical simulation results that stiffness of the MR damper can be varied with the current value and increase the damping forces with the reduced amplitude of excitation. Experimental and theoretical results of the MR damper characteristics demonstrate that the developed MR damper can be used for vibration isolation and suppression.


2021 ◽  
pp. 107754632110388
Author(s):  
Hongwei Lu ◽  
Zhifei Zhang ◽  
Yansong He ◽  
Zhi Li ◽  
Jujiang Xie ◽  
...  

The realization of the desired damping characteristics based on magnetorheological (MR) dampers is important for semi-active control and useful for the matching process of suspension damper. To reduce the cost of the control system and improve the output accuracy of the desired damping force, this study proposes an open-loop control method featuring an accurate inverse model of the MR damper and a tripolar current driver. The reversible sigmoid model is used to accurately and quickly calculate the desired current. Furthermore, the change characteristic of the desired current is analyzed qualitatively and quantitatively, which shows that the desired current needs to change suddenly to make the actual damping force velocity curve quickly approach the desired one. To meet the demand of the desired current, a tripolar current driver controlled by an improved PI control algorithm is proposed, which is with fast response and low noise. Finally, the bench test verifies that the control system can achieve different desired damping characteristics well, and the inherent error in this process is explained through the gap between the available damping force area and the desired damping characteristic curve and the crossover phenomenon of the dynamic characteristic curves of the MR damper.


Author(s):  
Anria Strydom ◽  
Werner Scholtz ◽  
Schalk Els

Magnetorheological (MR) dampers are controllable semi-active dampers capable of providing a range of continuous damping settings. MR dampers are often incorporated in suspension systems of vehicles where conflicting damping characteristics are required for favorable ride comfort and handling behavior. For control applications the damper controller determines the required damper current in order to track the desired damping force, often by using a suitable MR damper model. In order to utilise the fast switching time capability of MR dampers, a model that can be used to directly calculate damper current is desired. Unfortunately few such models exist and other methods, which often negatively affect the computational efficiency of the model, need to be used when implementing these models. In this paper a selection of MR damper models are developed and evaluated for both accuracy and computational efficiency while tracking a desired damping force. The Kwok model is identified as a suitable candidate for the intended suspension control application.


Author(s):  
Z. Liu ◽  
X. Han ◽  
Y. F. Liu

A nonlinear dynamic model of a large flow solenoid is presented with the multi-physics dynamic simulation software called SimulationX. Validation is performed by comparing the experimental results with the simulated ones. The dynamic characteristics of the large flow solenoid valve are analyzed. Different structural parameters are modified in this research and the diameter of the orifice is proved to be one of the most important parameters which influences the pressure response most.


2020 ◽  
Vol 25 (4) ◽  
pp. 504-512
Author(s):  
Robert Pierce ◽  
Sudhir Kaul ◽  
Jacob Friesen ◽  
Thomas Morgan

This paper presents experimental results from the development of a rear suspension system that has been designed for a mountain bike. A magnetorheological (MR) damper is used to balance the need of ride comfort with performance characteristics such as handling and pedaling efficiency by using active control. A preliminary seven degree-of-freedom mathematical model has also been developed for the suspension system. Two control algorithms have been tested in this study: on/off control and proportional control. The rear suspension system has been integrated into an existing bike frame and tested on a shaker table as well as a mountain trail. Shaker table testing demonstrates the effectiveness of the damper. Trail testing indicates that the MR damper-based shock absorber can be used to implement different control algorithms. Test results indicate that the control algorithm can be further investigated to accommodate rider preferences and desired performance characteristics.


Author(s):  
R. Scott Pierce ◽  
Caleb Whitener ◽  
Sudhir Kaul

This paper presents experimental results from the testing of a semi-active damping system in an off-road bicycle (bike). Magnetorheological dampers are being increasingly used in automotive applications to enhance damping capability of a suspension system or to mitigate the trade-off between ride comfort and handling. A magnetorheological (MR) damper requires a relatively low amount of energy to control damping characteristics, and behaves as a passive damper in the absence of any power input. This study investigates the use of a semi-active magnetorheological damper for the rear suspension of a mountain bike. The performance of this damper has been compared to the current shock absorber on the bike. All testing has been performed on a shaker table and the performance of the damper has been evaluated by comparing the input acceleration at the hub of the rear wheel to the acceleration at the seat of the bike. The main aim of this study is to investigate the viability of using an MR damper in a mountain bike suspension system. Test results indicate that the performance of the semi-active MR damper is comparable to the current shock absorber. Furthermore, the MR damper lends itself to hands-off control that will be investigated in a future study. Therefore, it can be concluded from preliminary testing that an MR damper can be used in a mountain bike to effectively control damping.


2014 ◽  
Vol 665 ◽  
pp. 601-606
Author(s):  
Xiao Chuan Liu ◽  
Shi Xing Zhu ◽  
Yong Gang Yang

The structure of a shock absorber based on magnetorheological (MR) damper with a metering pin is proposed, and structure of the magnetic circuit of MR damper is optimized. By drop tests, the damping characteristics of the shock absorber and damping effect are tested. The experimental results show that the shock absorber has the characteristic of a wide damping force adjustment range and lower energy dissipation. The maximum vertical load and shock absorber piston displacement can be changed at same drop height by changing the current. It has also been proved that shock absorber based on MR damper is better than conventional oleo-pneumatic shock absorber on adjustment of damping force.


Author(s):  
Shaopu Yang ◽  
Cunzhi Pan ◽  
Shuqi Guo

In this paper, a test model of a vibration isolation system with magnetorheological (MR) damper is introduced, and a simplified model using the time delay to describe the dynamic process of mechanical response and electromagnetic response for the MR damper is presented. Based on simulation, the performance evaluation with different control strategies, especially, the effects of time delay are investigated. The results show that the performance of the controlled system is highly dependent on the choice of the control strategies, and the effectiveness of semi-active on-off control is significantly determined by the time delay from the command current signal to the magnetic field of the MR damper.


2018 ◽  
Vol 877 ◽  
pp. 391-396
Author(s):  
Jitenkumar D. Patel ◽  
Dipal Patel

Mostly, magnetorheological damper research is going on flow mode and shear mode type of damper. Less work is carried out by researcher on squeeze mode type of damper. This will give higher force as compare to flow mode and shear mode type of MRF damper at low excitation. So, this kind of damper can be used as vibration isolation for high impact loading at low amplitude application like engine mount. Aim of this paper is optimized design of Squeeze mode damper for low amplitude application by using design of experiment tool. For design of squeeze mode type of MR damper magnetic field distribution is very important study to improve damping performance. Various parameters like length of coil, diameter of squeeze plate, current passing through coil, number of turns, area of coil and MR fluid gap are considered during optimization and optimization is done by using FEMM software It shows that length of coil, Number of turn and area of coil increases damping performance improves. Other design parameters are check out with mathematical model of MR damper with theoretical calculation like effect of frequency of excitation, diameter of squeeze plate, thick ness of squeeze plate and amplitude of excitation.


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