Magnetorheological Fluid Damper Research Articles

A Bi-Directional, Liquid-Spring-Magnetorheological-Fluid-Damper System

The goal of this study was to demonstrate the feasibility of a novel fail-safe, bi-directional liquid spring, controllable magnetorheological fluid damper (BDLS-CMRD). This research introduces a device with independently pre-set spring forces in compression and rebound combined with controllable MR fluid damping. The BDLS-CMRD can potentially replace traditional metal spring-damper suspension systems. Bulky and heavy metal spring-damper suspension systems can be upgraded to the smaller and lighter BDLS-CMRD, reducing the mass of vehicle suspensions. In this work, a BDLS-CMRD was designed, fabricated, tested and evaluated in three phases. The first design phase demonstrates the concept of a liquid spring with different spring forces in compression and rebound. The second phase incorporates viscous fluid damping of pure silicone fluid with the first phase BDLS. The final design phase combines a controllable magnetorheological fluid (MRF) damper with the first phase BDLS. This study presents the response of the BDLS-CMRD in a wide range of preloaded conditions and frequencies. Experiments were performed for sinusoidal displacements in the quasistatic and dynamic ranges to evaluate the performance of the BDLS-CMRD under different magnetic fields. The experimental results demonstrate that the device operates with significantly different spring forces from the compression to rebound regions, while providing passive viscous fluid damping or controllable MR fluid damping. This system has successfully demonstrated that the utility of a bi-directional liquid spring can be combined with the reliability of passive viscous fluid damping and the capabilities of controllable MR fluid damping into one compact and versatile device.

Scale-Based product family optimization design based on the improved AMPSO in selecting optimum strategy

Abstract The main contribution of this paper is to propose a two-stage scale-based product family design method (TPFDM) based on an improved adaptive mutation particle swarm optimization (AMPSO) algorithm. To do that, the problem involved in scale-based product family design is analyzed and modelled. A two-stage optimized design process is built to solve the problem. To build and optimize the product family platform, a multi-objectives model about the product family design problem is established. The multi-objectives problem and each parameter's sensitivity as well as variation index about objectives are solved via an intelligent optimization algorithm. The platform constants and non-platform variables are discriminated by sensitivity and variation index in the first stage. The main work of the second stage is to optimize products based on product platform via the intelligent optimization algorithm. Moreover, in order to overcome the early maturity phenomenon of the particle swarm optimization algorithm, an improved AMPSO algorithm is proposed to introduce the concept of the non-individual optimum strategy and the dominate strategy. Finally, aerial magnetorheological fluid damper family design is used as an example to demonstrate effectiveness and feasibility of the proposed method.

A Review on Structural Development of Magnetorheological Fluid Damper

Owing to unique advantages, magnetorheological fluid (MRF) dampers have been widely adopted in different fields of vibration control. Significant differences of structures occur in diverse fields due to the respective requirements, thus obtaining a large number of MR dampers. Having a good understanding of types, technical characteristics, comprehensive performance, and developing trend and their dependencies on structures are extremely conducive to innovative developments and a market selection. While the fundamental and partial structures are summarized in an existing review, the classification, latest technologies, and developing trend are not involved clearly. Therefore, the current survey aims at a comprehensive supplement in such aspects. The review begins with an introduction of the development, application, and classification. Then, details of three technical routes are revealed, and the development of each type is roughly analyzed. Finally, reflecting through this review, structures including a novel flow mode and miniature bypass valves have represented the currently structural and technical features. Fully considering the latest technologies and future requirements, the developing trend and a variety of applications will be anticipated.

Experimental Verification on Seismic Wave Damping for the Elevator with a Magnetorheological Fluid Damper

Experimental Verification on Seismic Wave Damping for the Elevator with a Magnetorheological Fluid Damper

Dynamic and Stability Analysis of the Machine Hydrostatic Slide with Magnetorheological Damper

Tangential dynamic behaviors of the machine hydrostatic slide with a magnetorheological (MR) fluid damper are studied, and the effect of the MR damper to control the vibration of the hydrostatic slide is discussed. The dynamic model of the hydrostatic slide with the MR damper is established, and the tangential vibration equation of linear and nonlinear is derived. The multidimensional incremental harmonic balance method (MIHBM) with discrete Fourier transform (DFT) is derived by which the nonlinear response and stability of the system are studied. The resonance response of the Duffing equation under the combined action of harmonic excitation and constant excitation is obtained. In order to investigate the vibration response of the hydrostatic slide with the MR damper in detail, the bifurcation diagram, phase diagram, and Poincaré map are given. Finally, the dynamic response of the machine hydrostatic slide with the MR damper is discussed, and it is verified that the MR damper can suppress the tangential vibration of the hydrostatic slide effectively and the constant controller can control the chaotic behavior of the system well.

The design and dynamic analysis of a lunar lander with semi-active control

The Moon is the nearest celestial body to the Earth and the starting point of the space exploration for the human being. The impact energy absorption and landing stability of lunar landers are extremely critical for lunar exploration. However, traditional landers cannot adapt to complex landing conditions and response to any unforeseen accidents during the landing process. Although some researchers have proposed the idea for the lander with MRF dampers, there are relatively few detailed structural designs and practical landing research studies. In this paper, we propose a detailed new type of lander with magnetorheological fluid dampers implemented as the primary struts, which can absorb the impact energy from landing. Its damping force is controlled by semi-active controlled currents based on the derived hydrodynamics of magnetorheological fluid dampers and can adjust to practical landing conditions. The simulation models of landers with the aluminum honeycomb and semi-active control are constructed in MSC Adams separately to compare their landing performances. Their simulation results show that this new type of lander can effectively reduce the largest acceleration by 26.18% under the largest acceleration response condition and the largest compression by 11.77% under the largest compression of primary struts condition. Its performance for more inclined and both smoother and rougher landing surfaces is better than that of traditional passive landers. It is believed that the proposed new type of lander is capable of landing on more complex and unexplored terrains for future lunar explorations.

Dynamic modeling and sliding mode control of single cylinder double annular channels MRF damper

In order to satisfy the adjusting of recoil system of the gun to different firing conditions, a magneto-rheological fluid (MRF) damper with double annular channel is proposed, which can satisfy the maximum recoil displacement and reduce the force acting on the gun carriage. The double annular channels MRF damper has less zero field damping force and has a larger range of resistance regulation. The dynamic model of MRF damper considering inertia effect is established, and the mechanical properties of MRF damper are tested. The experimental results shown that the calculated values are in good agreement with the experimental values. According to the gun recoil dynamic model of MRF damper, a sliding mode tracking controller based on constant velocity reaching law is designed, and the recoil process of the gun is simulated. The results shown that the MRF damper damping force under the sliding mode control algorithm has a plateau effect, which can be used in the recoil motion control of the gun.

Design and modeling analysis of a changeable stiffness robotic leg working with magnetorheological technology

Since animals can adjust the stiffness of their bodies and/or appendages to adapt to changing environments and internal states and tasks, a robotic leg with changeable stiffness would be of assistance in developing mobile terrestrial robots. In this article, we present an improved model of a robotic leg that can alter its stiffness in real time by changing the characteristics of magnetorheological fluid. This particular robotic leg has a changeable stiffness module, which consists of a rotating magnetorheological fluid damper, a torsional spring, and a linear spring. The rotary magnetorheological fluid damper is used to control the deformation of a torsional spring, which alters the stiffness of the leg. To describe the mechanical features of the leg, a simplified mechanical model was built and then various experiments were carried out to verify the changeable stiffness characteristics. The simulation experiments of dual-leg locomotion were carried out to investigate the locomotive performance, including walking speed, maximum torque of motor, height variants, and mechanical cost of transport. These results demonstrate the adaptability and advantages of this changeable stiffness robotic leg and also indicated that developing a terrestrial robot which can adapt to various complex environments and tasks would be a worthwhile exercise.

Vibration Analysis and Control of Nuclear Power Crane with MRFD

The nuclear power crane is required to have high security and stability, as its lifting mechanism and span structure are needed to perform predominantly in serious working conditions. A new vibration analysis and control method on the nuclear power crane is proposed to improve its stability, which is based on magneto rheological fluid damper (MRFD) and switch algorithm control strategy. The simulation is completed through dynamic model and control model. The experiment is accomplished in a serving crane. Both numerical simulated and experimental results show that the vibration of nuclear power crane is suppressed significantly with MRFD. It is proved that MRFD should be taken into consideration in the vibration control of nuclear power crane.

Simulation of Quarter-Car Model with Magnetorheological Dampers for Ride Quality Improvement

A semi-active suspension system using Magnetorheological (MR) damper overcomes all the inherent limits of passive and active suspension systems and combines the advantages of both. This paper gives a concise introduction to the suspension system of a passenger vehicle which is presented along with the analysis of semi-active suspension system using MR fluid dampers based on Bingham model. MR dampers are filled with MR fluids whose properties can be controlled by applying voltage signal. To further prove the statement, a quarter car model with two degrees of freedom has been used for modeling the suspension system the sprung mass acceleration of passive suspension system has been compared with the semi-active suspension system using the Bingham model for MRF damper. Simulink/MATLAB is used to carry out the simulation. The results drawn show that the semi-active suspension system performed better than the passive suspension system in terms of vehicle stability.

Low-energy structures embedded with smart dampers

Building structures, subject to dynamic loadings or external disturbances, may undergo destructive vibrations and encounter different degrees of deformation. Modeling and control techniques can be applied to effectively damp out these vibrations and maintain structural health with a low energy cost. Smart structures embedded with semi-active control devices, offer a promising solution to the problem. The smart damping concept has been proven to be an effective approach for input energy shaping and suppressing unwanted vibrations in structural control for buildings embedded with magnetorheological fluid dampers (MRDs). In this paper, the dissipation energy in MRD is studied by using results from induced hysteretic effect of structural vibrations while the fluid is placed under a controlled magnetic field. Then, a frequency-shaped second-order sliding mode controller (FS2SMC) is designed along with a low-pass filter to implement the desired dynamic sliding surface, wherein the frequency responses of the hysteretic MRD is represented by its magnitude and phase describing functions. The proposed controller can thus shape the frequency characteristics of the equivalent dynamics for the MRD-embedded structure against induced vibrations, and hence, dissipate the energy flow within the smart devices to prevent structural damage. Simulation results for a 10-floor building model equipped with current-controlled MRDs, subject to horizontal seismic excitations validate the proposed technique for low-energy structures with smart devices. The closed-loop performance and comparison in terms of energy signals indicate that the proposed method allows not only to reduce induced vibrations and input energy, but also its spectrum can be adjusted to prevent natural modes of the structure under external excitations.

Electromechanical characteristics and numerical simulation of a new smaller magnetorheological fluid damper

In order to develop a smaller magnetorheological fluid (MRF) damper and its corresponding analysis software, a new MRF damper with outer-coils and testing system was designed. The testing results show that the MRF has good mechanical properties when the damping gap is 1.5 mm. The smoothing damping force is only 1.0–4.0 N by adjusting the coil current from 0 A to 2 A, and it is linearly related to current through data fitting. The damping force versus velocity curve has obvious hysteresis characteristic, and an improved nonlinear dynamic model is proposed. Based on the model and linear function, electromechanical characteristics of the MRF damper can be simulated by Simulink, which provides an analysis platform for applications of the damper.

Experimental analysis of vibration isolation using hybrid magnet and magnetorheological fluid damper

This work analyzes the effect of magnetic field strengths of actuators on the performance of vibration isolation of quarter car model. Hybrid magnet and magnetorheological fluid damper with the nano- and micron-sized iron oxide particles are employed as actuators in parallel with the conventional elements of the car model. Experimental work has been carried out on a laboratory scale model of a two degree of freedom quarter car with the help of electrodynamic shaker, accelerometers, data acquisition card and LabVIEW software. The performance is evaluated based on suspension deflection, tire deflection and transmissibility ratio. The improvement in the performance of the combined effect of actuators is better than the conventional and individual elements.

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.

Control of transtibial prosthetic limb with magnetorheological fluid damper by using a fuzzy PID controller

The damping characteristic of a healthy limb changes throughout the gait cycle. However, for amputees who are wearing mechanically passive damping prosthesis, the lack of ability to change the damping values might expose them to injuries and health problems. The use of magnetorheological fluid damper in prosthetic limb, which provides wide dynamic range, seems to be able to prevent these conditions from happening, due to its response to the magnetic field. The magnetorheological fluid, a type of smart material that is capable of altering its rheological property, changes its viscosity subjected to the intensity of the external magnetic field. Thus, due to this property, magnetorheological fluid damper covers the advantages of both passive and active dampers. This work explores the implementation of magnetorheological fluid damper in transtibial (below knee) prosthetic limb utilizing adaptive control techniques via simulation studies. An experimental study was done to observe the relationship of the force generated by the damper to the applied current. In addition, fuzzy-proportional–integral–derivative controller was implemented to ensure that the damper performs well, even at varying frequencies.

Optimal control with fuzzy compensation for a magnetorheological fluid damper employed in a gun recoil system

This article presents an optimal control strategy with fuzzy compensation for a magnetorheological fluid damper in control of a full-scale gun recoil buffering system. The novel control strategy combines the optimal control, in which no measurement feedback needed and the fuzzy logic control which is independent of any theoretical model. The theoretical optimal controllable damping force rule, as a fail-safe control output when the measurement system fails under the extreme condition of impact loading, is derived from the analytical solution of the kinematic equation of the recoil system with a magnetorheological damper. A one-dimensional fuzzy controller and a two-dimensional fuzzy controller are both designed and performed by simulation in order to evaluate the effectiveness of fuzzy control strategy as compensation in the magnetorheological recoil system. A magnetorheological damper for the real firing impact loading is designed and manufactured. Furthermore, an experimental study is carried out to evaluate the optimal control strategy with fuzzy compensation for magnetorheological damper on a firing test rig. The experimental results indicate that the proposed control strategy in this article obtains better buffering performance comprehensively compared with the conventional control strategies.

Characteristics, Optimal Design, and Performance Analyses of MRF Damper

Magnetorheological fluid (MRF) damper is one of the most promising semiactive devices for vibration control. In this paper, a shear‐valve mode MRF damper for pipeline vibration control is proposed. The dynamic model and the state equation of the pipeline are established and the linear quadratic regulator (LQR) is used to generate the optimal damping force of MRF damper. The design concept considering the structure and the electromagnetic properties simultaneously is discussed in detail. A mathematical model of the relation between shear stress and control current based on interpolation method is established. Finite element analysis (FEA) software COMSOL is selected to simulate the magnetic field and electromagnetism‐thermal field of the MRF damper. A computational method based on the simulation model is established to calculate the shear stress. In order to reduce the magnetic leakage, a method of adding magnetism‐insulators at both ends of the piston head is presented. The influence of control current, displacement, and velocity on mechanical performance of the proposed MRF damper is experimentally investigated. The test results show that the performance of the MRF damper is basically identical with the theoretical prospective and the simulation conclusions, which proves the correctness and feasibility of this design concept.

A Verification on Impact Force Reduction and Ride-comfort Improvement for the Elevator with a Magnetorheological Fluid Damper

A Verification on Impact Force Reduction and Ride-comfort Improvement for the Elevator with a Magnetorheological Fluid Damper

Variable stiffness mechanisms of dual parameters changing magnetorheological fluid devices

Magnetorheological fluid (MRF) dampers are widely used as the variable damping devices in the semi-active vibration control system. In order to further improve the vibration reduction performance, a variable stiffness MRF damper with two chambers and two springs has been proposed recently. According to the test results, both of the damping and stiffness of the device can be controllable by changing the applied current independently. However, the mechanisms of variable stiffness for this device are still not clear. In this paper, the force transmissions of the parts of the variable stiffness MRF damper are analyzed, which reveals the variable stiffness mechanisms of dual parameters changing MRF devices. There are three stages for the variable stiffness MRF damper due to the friction and the yield of MR fluid. These stages can be controlled by the applied current of the different chambers, which changes the equivalent stiffness of the device. The proposed modelling of the device is verified by simulations and tests. In addition, the relationships between the equivalent stiffness and the parameters of the device are derived, which provide the design guidance for the variable stiffness MRF dampers.

Experimental Verification of Effects in an Emergency Stop by Installation of Magnetorheological Fluid Damper to an Elevator

In the countries sailing with an economic tailwind, many skyscrapers are going up. These buildings require systems of high-speed, safety, and comfortable elevators for its speedy vertical transportation. If the drives of elevator fail, an emergency stop device is supposed to work immediately for saving passengers lives in the elevator cage, because the elevator has outrageous potential energy to the ground level and kinetic energy. Its dangerousness is nothing compared to that in railways as surface transport. In order to reduce impact force to passengers in emergency stoppage, the authors had already proposed a safe and dependable magnetorheological fluid (MRF) semi-active damper (i.e., MRF damper) put between an emergency stop device and an elevator cage. In this paper, in order to evaluate the effects of the MRF damper, we would like to make up a test installation, which is composed of an MRF damper, a spring, an elevator cage, linear servo mechanics with a ball screw for generating the brake force of emergency stop device, sensors, and a digital controller with Labview. In addition, we would like to verify the validity of our system by many experiments.