Characteristics Of Magnetorheological Damper Research Articles

Control Voltage Effect on Operational Characteristics of Vehicle Magnetorheological Damper

Considering the increasingly large-scale application of magnetic fluids in various industries, we can confidently state that in the near future magnetorheological dampers will be widely used in adaptive automotive suspensions due to their operational flexibility and simplicity of controlling damping forces by changing the magnetic fluid properties according to parameters of surrounding electromagnetic field. The antivibration efficiency during operation is achieved by regulating the hydraulic resistance of the “magnetic” shock absorber by applying voltage to the windings of its coil. In addition to the physical properties of the oil used in the “magnetic” shock absorber, the viscosity of the working magnetorheological fluid is greatly influenced by the shape of the control signal. The paper focuses on the theoretical aspects of constructing a mathematical model of ac magnetorheological damper and presents the results of a computer experiment to assess effectiveness of its use as part of the adaptive suspension a passenger vehicle. In this case, the actual parameters of the “magnetic” shock absorber, used in modeling the dynamic process, were determined experimentally on a test bench, and the adequacy of the developed mathematical model was confirmed by the results of a semi-natural experiment. Using a verified model, the magnetorheological damper characteristics were obtained and compared for various forms of control signal, including rectangular voltage pulses of various frequencies and duty cycles, sinusoidal pulses and constant voltage signals. The analysis of the antivibration efficiency was carried out on the basis of the developed “quarter” model of a semi-active car suspension with a verified submodel of a magnetorheological damper integrated into its structure. Moreover, the simulation scenarios were based on the selected strategy for controlling the voltage supplied to the windings of the “magnetic” shock absorber. As the results of theoretical and experimental studies have shown in terms of energy consumption, expansion of the working area of the damping characteristic and achieving smooth control of the damping force, the most effective is the use of a sinusoidal pulse voltage signal in the control circuit, which ensures a reduction in both the amplitude and damping time of oscillations. However, when de-signing and manufacturing a controller, creating a pulse modulator for generating sinusoidal pulses coinciding in phase and frequency with the vibrations of the car body is very difficult due to the random nature of external disturbances from the road surface. When a constant voltage is applied to the magnetorheological damper winding, the damping properties of the suspension are also improved compared to the basic design based on a traditional hydraulic shock absorber. Moreover, there is a proportional relationship between the voltage supplying the damper, the amplitude and damping time of the vibrations of the car body is observed. An increase in the control signal voltage from 1 to 2 V leads, in comparison with passive control of a magnetic shock absorber, to a decrease in the maximum amplitude of vibrations of the car body by 6.25 and 11.25 %, respectively, and a decrease in the vibration damping time by 0.72 and 1.41 s.

Simulation of multi – field coupling damping characteristics of magnetorheological damper in ring system by artificial intelligence method

A new kind of smart material called Magnetorheological (MR) has attracted a lot of attention among designers due to its mechanical properties that can alter in a controlled fashion by an external magnetic field. Regarding this issue, in the current work, for the first attempt, the dynamic stability of a sandwich shell made of MR core and graphene nanoplatelets reinforced composite (GPLRC) face sheets is presented. Using the role of the mixture and modified Halpin–Tsai model, the effective material properties of GPLRC face sheets are presented. Via Hamilton’s principle and linear viscoelastic theory, the governing equations of the current sandwich structure are developed. Also, compatibility equations for accurate modeling of the sandwich structure are presented. The discrete singular convolution integration method (DSC-IM) for prediction of nth-order derivatives of a sufficiently smooth function via weighted linear sum function of the amounts at each separated point in the throughout allowable input range is presented. For more verification, a deep neural network as an artificial intelligence method is presented. Finally, the results show that GPL’s weight fraction, viscoelastic foundation, the geometry of GPLs, and geometry of the structure have an important role in dynamic stability and modal loss factor parameter of sandwich shells.

Effect of magnetorheological damper parameters on dynamic responses of a full-vehicle suspension system

This paper investigates how magnetorheological (MR) damper parameters affect the dynamic response of a full-vehicle suspension system in much detail. The constitutive mechanical model and characteristics of MR damper are firstly obtained and analyzed, which preferably describes the physical parametric features of MR damper. To simplify the impact analysis model, a full-vehicle control model with the PID decoupling controller based on the inverse model for MR damper is established. In line with the above developed full-vehicle model, the impact analysis of input current on the suspension dynamic responses is obtained by updating the equivalent damping coefficient of MR damper. The effect of MR damper parameters on the dynamic responses is investigated based on the RMS of the percentage-based slope, and its wear effect caused by the friction loss in practical application is also discussed. The experimental results show that the piston diameter and cylinder inner diameter have greater influence on the dynamic responses than other influence parameters include the coil turns, effective piston length and piston rod diameter. In contrast, the apparent viscosity of MR fluids has little influence on the dynamic responses. In addition, the MR semi-active suspension has better stability than the passive suspension when parameter perturbation occurs in the suspension system. It is necessary to ensure that MR damper has the suitable maximum output damping force and large enough dynamic range simultaneously.

Comparison of dynamic models based on backbone curve for rotary magneto-rheological damper

To realize the accurate control of magneto-rheological system, the nonlinear dynamic model as the joint of damper and control strategy is worthy of being investigated. In this study, the modeling methods based on the backbone curve are proposed to portray the dynamic characteristics of magneto-rheological damper. The modeling methods contain the phase lag method and the hysteresis division method. Six novel algebraic models are deduced from the two methods and compared systematically. The parameters identification of models is conducted by the nonlinear least square method. The nonlinear least square optimization problem is solved by the Levenberg–Marquardt algorithm. The evaluation indexes including the root-mean-square error, mean deviation and computation time are calculated to evaluate the accuracy and feasibility of the novel models. Results show that the modeling methods and their models can describe the nonlinear hysteretic characteristics with feasibility and accuracy.

Experimental Evaluation of Magnetorheological Damper Characteristics for Vibration Analysis

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.

Magneto-rheological damper design characteristics for vehicle airbag replacement

Vehicle crashes continue to occur despite all the human efforts to prevent them resulting in injuries and loss of lives. The implementation of airbags has been shown to offer passenger safety in a collision. However, premature deployment and malfunction of airbag has resulted in fatalities and injuries to drivers and front seat passengers. In this study, a magneto-rheological (MR) damper is used as a replacement of airbag in vehicles to serve as a protective system. MR damper is a smart damping device which can be programmed to dynamically absorb shocks and high impact force when used in application such as passenger cars. In this paper, G-force profile of the airbag vehicle crashing system is compared with the G-force profile obtained from the MR damper vehicle crashing system. Subsequently, for this purpose MR damper characteristics are designed and Fuzzy Logic Controller (FLC) and Proportional Integral Derivative (PID) controller are proposed for MR damper current control. Simulation results proved that fuzzy based MR damper system yields better results compared to PID based MR damper system and airbag vehicle crashing system.

Experimental Study of Damping Characteristics of Air, Silicon Oil, Magneto Rheological Fluid on Twin Tube Damper

This paper is inclined towards the study of damping characteristics of magneto rheological damper under different fluid environments i.e. Air damping, viscous damping and MR damping. The twin tube damper was designed to conduct the experiments and to analyze the dynamic behavior under these conditions. The results show that MR fluid has good damping characteristics than that of the other fluids due fluid-particle interaction and friction near fluid-structure interface. In addition it can provide high damping rate under the influence of magnetic field. Finally, the damping phenomenon of the MR fluid is discussed in depth to support the experimental results

Influence of MR damper modeling on vehicle dynamics

The influence of magneto-rheological damper modeling in vehicle dynamics analysis is studied. Several tests using CarSim™ compare a four-corner controlled semi-active suspension for two different magneto-rheological damper models. The magneto-rheological damper characteristics were identified from experimental data. A model-free controller discards the influence of control and emphasizes the compliance of the magneto-rheological damper model; the characteristics of the vehicle index performance considered were comfort, road holding, handling, roll and suspension deflection. The comparison for magneto-rheological damper dynamics and semi-active suspension covers the automotive bandwidth. The results show that high precision of a magneto-rheological damper model as an isolated feature is not enough. The magneto-rheological damper model, as a component of a vehicle suspension, needs to simulate with passive precision and variable damping forces. The findings exhibit the requisite of accurate models for evaluation of semi-active control systems in classic tests. The lack of the friction component in a magneto-rheological damper model leads to an overestimation in handling and stability.

New Non-Linear Modeling and Optimal Controlling for MR Damper under Impact Load

Magnetorheological (MR) fluid is capable of changing its rheological characteristics under magnetic field. Controllability is one of the advantages of MR damper. Up to now, the dynamic characteristics of MR damper under impact loads have not been well known by researchers. In this paper, a new type of dynamic model for MR damper subject to impact load is derived. And in this novel model, it is pointed out that the square damping item and the inertia force item are two important factors which influence the total damping force in impact condition. The adding two items make the model more exactly describing its dynamic characteristics of MR damper in impact condition. This action makes the established model easier to do control analysis. Because of the polynomial form and a fixed coefficient, it is indicated that the optimization control method is a good choice for MR damper to track the demanded impact curves. Simulation analysis results prove that based on its controllability of damping force MR damper provide, its vibration-reduction and shock-resistant properties of MR damper under impact load will also be greatly improved.

Research on low-frequency mechanical characteristics of the MR dampers in ship isolators

A new isolator composed of a steel rope spring and a magneto-rheological (MR) damper was designed and a study on low-frequency mechanical characteristics of MR dampers in isolators was carried out. It used the characteristics of the MR damper, such as fast response, controllable damping, small energy consumption, wide dynamic scope, and great adaptation. The relationships between MR damping forces and influencing factors were analyzed based on experimental data. The results show that damping force is not only related to structural dimensions, but also closely related to controllable current and vibration frequency. Finally, the empirical formula for damping forces was corrected, and the relationship between correction coefficients and factors analyzed.

PRELIMINARY DESIGN PROCEDURE OF MR DAMPERS FOR CONTROLLING SEISMIC RESPONSE OF BUILDING STRUCTURES

In this paper, a preliminary design procedure of magnetorheological (MR) dampers is developed for controlling building response induced by seismic excitation. Hysteretic biviscous model which is simple and can describe the hysteretic characteristics of MR damper, is used for parametric studies. The capacity of MR damper is determined as a portion of not the building weight but the lateral restoring force. A method is proposed for the optimal placement and number of MR dampers, and its effectiveness is verified by comparing it with the simplified sequential search algorithm. Numerical results indicate that capacity, number and placement can be reasonably determined using the proposed design procedure.

Modelling and testing of the force-generating characteristics of magnetorheological dampers

This paper presents a model for a magnetorheological damper, and subsequent experimental results. Two cylindrical piston type MR dampers, which develop almost identical friction and viscous forces, were tested. These dampers were designed to provide different combinations of fluid flow and magnetic field orientation. In one damper, the magnetic field and magnetic field orientation are designed to be primarily parallel to each other, and in the other damper, the field and flow are designed to be perpendicular. Each actuator was tested under different conditions of applied current and piston speed, and the force-generating characteristics were studied. The two damper designs will be introduced and a comparison between results from the model and the experiments will be made. In general, the model captures the forcegenerating characteristics of the dampers; however, it does not account for field-flow orientations.