Papers by Keyword: MR Damper

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Authors: Maguid H.M. Hassan
Abstract: 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.
Authors: Xing Xing Zhu, Si Hong Zhu
Abstract: In order to further reduce the vibration transmitted from vehicle to driver, a new model of driver scissors linkage seat suspension was put forward, in which an air spring with auxiliary chamber and a MR damper are between the face and floor of the seat. The motion differential equation of this seat suspension system was established and the theoretical computing formulation of it’s equivalent vertical stiffness, equivalent damping coefficient, natural frequency and damping rate were deduced. Besides, taking HY-Z04 scissors linkage seat, SK37-6 air spring of ContiTech and RD-1005-3 MR damper of LORD as an example, the equivalent stiffness and damping coefficient in different conditions of the air spring pressure, the sprung mass, the orifice diameter and MR damping were computed and analyzed. The study results show that the air spring pressure, the sprung mass, the orifice diameter and MR damping all have obvious influence on the equivalent stiffness and damping coefficient, so the seat comfort can be improved by changing the air spring pressure, the orifice diameter and MR damping according to driver’s weight and road condition.
Authors: Jin Huang, Jian Min He, Guo Ping Lu
Abstract: Magnetorheological (MR) dampers are the semi-active control devices that use MR fluids to produce controllable dampers. In this paper, the design method of the cylindrical MR damper is established. Bingham model is used to describe the constitutive behavior of MR fluids subject to an applied magnetic field. The equation for the damping force is derived to provide the theoretical foundation for the design of the damper. Based on this equation the engineering expressions for the gap and effective length of the annular MR fluid between the piston and the outer cylinder are derived. The result shows that with the increase of the applied magnetic field strength, the damping force is increased. The dimensions of the gap and length can be calculated when the required damping force, the velocity of the piston, and the desired control damping force ratio are specified.
Authors: Shang Liu, Xiao Long Zhang
Abstract: The subject comesfrom major national special project in Kunming Machine Tool Factory which oursupervisor is working on currently. This report is the analysis of overallstructure of magnetorheological dampers,main technical features andperformance. It also provides a brief introduction to the main features of MRFand rheological principle, as well as the calculation of magnetorheologicaldamper size design, and also constructs the magnetorheological damper simulationmodel based on the magneto-rheological dampers structural features. With theTHM65160 CNC machine structure, we designed specifically on the localapplication of magneto-rheological dampers for varying magnetic flux dampermounted machine made ​​dynamic performance test responses. Based on this,magnetorheological dampers combine structural and performance characteristics,simulating the motion by using ADMS.
Authors: Xiao Mei Liu, Yi Jian Huang, Hong You Li, Qing Juan Zheng, Yu Ying Shi
Abstract: A generalized element which has the behaviors both of dashpot and spring is utilized to describe the visco-elasticity of a type of MR (Magneto-Rheological) Damper. A fractional derivative equation of motion which needs 4 parameters is developed to consider the nonlinear characteristics of the MR Damping system. It is demonstrated that the controlling current affects the order of the fractional system significantly, the increasing of the currents lead to the increasing of systemic order, strengthen the influence of viscosity remarkably and weaken the influence of inertia simultaneously. Nonlinear characteristics for shearing thin MRF damping system are also studied.
Authors: K. Hemanth, A. Ganesha, Hemantha Kumar, K.V. Gangadharan
Abstract: A magneto rheological damper is a damper filled with magneto rheological fluid, which is controlled by a magnetic field. This allows the damping characteristics of the shock absorber to be continuously controlled by varying the force of the electromagnet. This type of shock absorber has several applications, most notably in semi-active vehicle suspensions which may adapt to road conditions, as they are monitored through sensors in the vehicle. This paper presents magnetic saturation analysis of non-parametric model of magnetorheological (MR) damper using ANSYS for improvement of the higher force with optimal current and MATLAB/Simulink simulation for quarter car model equipped with MR damper to conduct dynamic studies of the system using skyhook controller and comparative study for passive and semi-active system.
Authors: Yong Feng Du, Yan Hui Liu, Hui Li
Abstract: This paper presents a numerical simulation of anti-overturning control of serially connected isolation system using an imagined novel device by combining piezo electric foot and MR tube support. In the vibration isolation of a serially connected electric device which is a real project and was installed on an overhead frame, overturning was observed as a determinant failure mode. To counter for this overturning problem, several additional bolts were used in the isolation layer which decreased the isolation effect. This paper further proposed a semi-active solution using a device for providing anti-overturning moment without increasing the seismic response of the superstructure. This paper presents the idea of the control device set-up and provides a vibration control algorithm, as well the range of validity of parameters of the plant.
Authors: Gwang Hee Heo, Chung Gil Kim, Seung Gon Jeon, Eun Ji Kim
Abstract: Earthquake inflicts damage on bridges in various ways. In this research an experimental study was carried out to decrease the damage caused by the pounding of bridges as earthquake load was added. For the experiment, we designed a model of successive bridge composed of a reinforced concrete bridge top and I section steel. At each bridge pier was placed a rubber bearing which was frequently used for seismic isolation. As for damper, we ourselves designed and produced a MR damper of 30 KN. Five experimental conditions were given ranging from without damper, with damper but no electricity input, with damper and electricity input, each with two different algorithms. For the experiment, we inflicted a 50% reduced wave of Kobe earthquake horizontally on the model, and compared the displacements and power data under each condition. The result proved that the MR damper of our own design was effective to prevent the successive bridge model from colliding by exerting a sizable amount of influence on its displacement and power data.
Authors: Maciej Rosół, Bogdan Sapiński, Mateusz Knapik
Abstract: The paper presents the conditioning system prototype intended for an electromagnetic generator supporting an MR damper in self-powered vibration reduction systems. The system engineered in the form of an electronic circuit comprises the following blocks: the MR damper control coil supply, self-powering, measurement and the microcontroller. The self-powering function consists in supplying the microcontroller from the generator, assuming that the voltage is larger than that required to power the microcontroller, otherwise the microcontroller will take up energy from a battery since the system has also the battery charging option. The performance of the system was verified through experiments where it acted as a component of a vibration reduction system.
Authors: Min Sang Seong, Kum Gil Sung, Seung Bok Choi
Abstract: This paper presents damping force control performances of a magnetorheological (MR) damper via new control strategy considering hysteretic behavior of the field-dependent damping force. In order to achieve this goal, a commercial MR damper which is applicable to passenger vehicle is adopted and its field-dependent damping force is experimentally evaluated. Since the field-dependent damping force shows the hysteretic behavior which significantly affects to control characteristics of the system, Preisach hysteresis model for the MR damper is established and its first order descending (FOD) curves are experimentally identified. Subsequently, a feed-forward compensator strategy for the MR damper is formulated and damping force control is evaluated. In addition, vibration control performances are experimentally evaluated with quarter-vehicle test facility.
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