Design and Analysis of Magneto-Rheological Dampers under Impact Loads

2013 ◽  
Vol 295-298 ◽  
pp. 2045-2048
Author(s):  
Xiao Ming Han ◽  
Yu Cheng Bo ◽  
Qiang Li ◽  
Ji Huang

In order to improve recoil mechanism’s buffering function of automatic weapon, using Newton’s second law, its recoil movement is analyzed and design model of magneto-rheological (MR) damper under impact loads is built. Structure parameter and control strategy are defined. Dampers’ characteristic curves at different magnetizing currents and different recoil speeds are tested on a damper indicator test bench. Some weapon’s recoil forces are artificially computed. The research results indicate that MR dampers have a perfect damping plateau effect. Recoil force of automatic weapon will be reduced by a big margin using the property that MR fluid can change at applied magnetic to control damping rules.

2015 ◽  
Vol 2015 ◽  
pp. 1-20 ◽  
Author(s):  
K. Sarp Arsava ◽  
Yeesock Kim

Magnetorheological (MR) damper has received great attention from structural control engineering because it provides the best features of both passive and active control systems. However, many studies on the application of MR dampers to large civil structures have tended to center on the modeling of MR dampers under seismic excitations, while, to date, there has been minimal research regarding the MR damper model under impact loads. Hence, this paper investigates nonlinear models of MR dampers under a variety of impact loads and control signals. Two fuzzy models are proposed for modeling the nonlinear impact behavior of MR dampers. They are compared with mechanical models, the Bingham and Bouc-Wen models. Experimental studies are performed to generate sets of input and output data for training, validating, and testing the models: the deflection, acceleration, velocity, and current signals. It is demonstrated that the proposed fuzzy models are effective in predicting the complex nonlinear behavior of the MR damper subjected to a variety of impact loads and control signals. The proposed fuzzy model resulted in an accuracy of 99% to predict the impact forces of the MR damper.


2012 ◽  
Vol 479-481 ◽  
pp. 1200-1204 ◽  
Author(s):  
Shao Na Liu ◽  
Shi Rong Yan ◽  
Shu Wei Li ◽  
Yao Gang Zheng

Comfort of the vibratory road roller is an important research title. A 2-DOF non-line model is set up, which is more close to the actual situation of the vibratory road roller. A simulation using MATLAB/SIMULINK is carried out to validate this model and study its dynamic characteristic and analyze the motion laws of its housing and wheel. A kind of Magneto-rheological (MR) damper is designed which has been widely used in automotive and bridge damping in recent years, and applied to a vibratory road roller to control it. The control strategy uses fuzzy control. The results indicate that the damping performance of the vibratory road roller which applied MR damper is improved remarkably.


2001 ◽  
Vol 8 (3-4) ◽  
pp. 147-155 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor

The application of magneto rheological dampers for controlling recoil dynamics is examined, using a recoil demonstrator that includes a single-shot 50 caliber BMG rifle action and a MR damper. The demonstrator is selected such that it can adequately represent the velocities that commonly occur in weapons with a recoil system, and can be used for collecting data for analyzing the effects of MR dampers on recoil dynamics. The MR damper is designed so that it can work effectively at the large velocities commonly occurring in gun recoil, and also be easily adjusted to reasonably optimize the damper performance for the recoil demonstrator. The test results show that it is indeed possible to design and use MR dampers for recoil applications, which subject the damper to relative velocities far larger than the applications that such dampers have commonly been used for (i.e., vehicle applications). Further, the results indicate that the recoil force increases and the recoil stroke decreases nonlinearly with an increase in the damping force. Also of significance is the fact that the adjustability of MR dampers can be used in a closed-loop system such that the large recoil forces that commonly occur upon firing the gun are avoided and, simultaneously, the recoil stroke is reduced. This study points to the need for several areas of research including establishing the performance capabilities for MR dampers for gun recoil applications in an exact manner, and the potential use of such dampers for a fire out of battery recoil system.


2008 ◽  
Vol 56 ◽  
pp. 218-224
Author(s):  
Maguid H.M. Hassan

Smart control devices have gained a wide interest in the seismic research community in recent years. Such interest is triggered by the fact that these devices are capable of adjusting their characteristics and/or properties in order to counter act adverse effects. Magneto-Rheological (MR) dampers have emerged as one of a range of promising smart control devices, being considered for seismic applications. However, the reliability of such devices, as a component within a smart structural control scheme, still pause a viable question. In this paper, the reliability of MR dampers, employed as devices within a smart structural control system, is investigated. An integrated smart control setup is proposed for that purpose. The system comprises a smart controller, which employs a single MR damper to improve the seismic response of a single-degree-of-freedom system. The smart controller, in addition to, a model of the MR damper, is utilized in estimating the damper resistance force available to the system. On the other hand, an inverse dynamics model is utilized in evaluating the required damper resistance force necessary to maintain a predefined displacement pattern. The required and supplied forces are, then, utilized in evaluating the reliability of the MR damper. This is the first in a series of studies that aim to explore the effect of other smart control techniques such as, neural networks and neuro fuzzy controllers, on the reliability of MR dampers.


1999 ◽  
Author(s):  
Mehdi Ahmadian ◽  
James C. Poynor ◽  
Jason M. Gooch

Abstract This study will examine the effectiveness of magneto-rheological (MR) dampers for controlling shock dynamics. Using a system that includes a 50-caliber rifle and a magneto-rheological damper, it is experimentally shown that MR dampers can be quite effective in controlling the compromise that commonly exists between shock forces and strokes across the shock absorber mechanism. A series of tests are conducted to demonstrate that different damping forces by the MR damper can result in different shock-force/stroke profiles. The test results further show that MR dampers can be used in a closed-loop system to adjust the shock loading characteristics in a manner that fits the dynamic system constraints and requirements.


Author(s):  
Mehdi Ahmadian ◽  
Xubin Song

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.


2000 ◽  
Author(s):  
Norman M. Wereley ◽  
Nicolas Costes

Abstract We will assess the capabilities of physically motivated MR dampers to mitigate ground resonance instability and control the damping level of rotor lag modes. The objectives of this research are threefold: (1) develop a methodology for the integration of the MR damper into a classic linear ground resonance analysis assuming an isotropic rotor hub (all dampers and blades similar) and an anisotropic rotor hub (due to lag damper dissimilarity due to damage, for example), (2) assess whether MR dampers can stabilize a rotor system that exhibits unstable ground resonance, (3) assess whether MR dampers can stabilize a rotor which exhibits unstable ground resonance behavior due to lag damper degradation or damage. The analyses developed in this study show that MR dampers are feasible for achieving these goals.


Author(s):  
R.B. Soujanya ◽  
D.D. Jebaseelan ◽  
S. Kannan

Passenger’s comfort in moving vehicles depends on the quality of the ride. The major cause of discomfort is the vibration transmitted to passengers due to the road irregularities. For a comfortable ride on a vehicle, vibration must stay within prescribed standards. In the present work, an attempt was made to show that, the vibrations can be limited with the use of Magneto-rheological (MR) dampers for varying road profiles than the passive damping methods. MR dampers are semi-active control devices that use MR fluids to produce controllable damping force as they are known to exhibit nonlinear behaviour. Multi body dynamic studies were done to study the response of the system using a quarter car model. In this paper, passive damping (viscous damping) was considered at natural frequency of 1.012Hz, the response of damping was observed after 10s and the acceleration was found to be 6m/s2. When MR damper is employed as the magnetic force increases, the response of the damping was better than the passive damping, at 1.2A it comes down to 0.55m/s2, and the vibration gets dampened after 1.75s. Hence, from this study it is concluded that the MR damper can be employed in automobile for better ride comfort.


Author(s):  
Fernando D. Goncalves ◽  
Jeong-Hoi Koo ◽  
Mehdi Ahmadian

This paper offers a method and an experimental example of determining the response time of Magneto-Rheological (MR) dampers. The response time of MR dampers for automotive suspension applications is valuable information because it is one of the key factors that determine the practical effectiveness of the use of MR dampers in vehicles. However, a detailed description of the response time of MR dampers is seldom given in the literature. Furthermore, the methods of computing the response time are not discussed in detail. Therefore, this study intends to develop a method for experimental determination of the response time of MR dampers for automotive suspensions. A triangle wave that maintains a constant velocity across the damper is proposed as the input to use in experiments. This triangle wave ensures a constant velocity across the damper in order to accurately evaluate the response time of the MR damper. The response time was defined as the time required to make the transition from the initial state to 63.2% of the final state, or one time constant. The time constant is a measure of how long it takes a system to respond to a given input. In other words, the response time is the time necessary for the damper to achieve the desired force upon activation. To demonstrate the method, the response time was found for an MR damper particularly designed and fabricated for vehicle applications. Two cases were considered: activation response time of the damper and deactivation response time of the damper. Both cases were studied during the rebound stroke of the damper. It was found that the response time of the MR damper under activation and deactivation was 15.4 ms and 13.9 ms respectively. The results are comparable to those found in the literature.


2019 ◽  
Vol 20 (1-2) ◽  
pp. 57-61
Author(s):  
Wiesław Grzesikiewicz ◽  
Michał Makowski

We considered of a vehicle model equipped with controlled magneto-rheological (MR) dampers and controlled aerodynamic elements. The vibrations of the vehicle moving at high speed during acceleration and braking are analysed. The purpose of this analysis is to determine the effect of forces generated on aerodynamic elements on vehicle vibrations and changes in wheel pressure on the road surface during acceleration and braking. The presented work presents the results of numerical investigations obtained on the basis of the developed vehicle model.


Sign in / Sign up

Export Citation Format

Share Document