Magnetorheological Fluid Damper Research Articles

Robust fuzzy output feedback control for a magnetorheological semi-active air suspension system with time-delay and actuator saturation

Magnetorheological fluid (MRF) dampers have been utilized in semi-active air suspension (SAAS) due to their attractive advantages. This paper investigates a novel robust fuzzy output feedback controller for semi-active air suspension with MRF damper (SAAS-MRFD), considering time delay and actuator saturation. An aero-thermodynamics theory is first utilized to describe the nonlinear air spring. The damping force of the MRF damper is represented by a hyperbolic tangent model. The interval type-2 (IT-2) Takagi–Sugeno (T-S) fuzzy method is second employed to capture those nonlinearities of the air spring and MRF damper. Considering the difficulty to measure all states, a novel dynamic output feedback (DOF) controller is developed by an appropriate Lyapunov–Krasovskii function and the reciprocally convex technique with consideration of time delay, actuator saturation, and output constraints. The effectiveness of the proposed controller is validated by both simulation and a quarter-car test rig (QCTR). The results indicate that the proposed controller has better performance in vibration reduction than the recent similar controllers in the literature.

Study on the dual-segment arctangent model of magnetorheological damper (MRD)

Abstract Magnetorheological fluid damper (MRD) is a damping device that utilizes the instantaneous variable characteristics of magnetorheological fluid (MRF) in magnetic field to control damping force. At present, there are some problems with the existing mechanical parametric models of MRD, such as the complexity of parameters in the Bouc-Wen model, low model accuracy, and the inability of the Bingham model to accurately capture the hysteresis characteristics of damping force with velocity variation. In response to these issues, on the base of MRD performance testing, a dual-segment arctangent model based on arctangent function is proposed. This model uses the arctangent function to describe the nonlinearity of the damping force output curve. And using piecewise fitting method to accurately capture the hysteresis characteristics of the output curve. Compared with existing parametric models such as the Bingham model, Sigmoid model, Bouc-wen improved model, et.al., the dual-segment arctangent model shows simpler parameters and higher model fitting accuracy. The comparative analysis of the fitting results based on experimental data confirms the effectiveness and accuracy of the proposed model, providing valuable reference for the development of high-precision MRD mechanical models.

Research on vertical vibration characteristics of rolling mill based on magnetorheological fluid damper absorber

The study of rolling mill vibration theory has always been a scientific frontier in the field of rolling forming, which is very important to the quality of sheet metal and the stable operation of equipment. A magnetorheological fluid damper absorber is designed to control the nonlinear vertical vibration of rolling mill. Considering the fractional order and delay factors in the control effect of magnetorheological fluid, the fractional order delay nonlinear vertical vibration equation with magnetorheological damping damper is established. The amplitude-frequency characteristic equations of the main resonance and sub-resonance of the system are solved by multi-scale method. The effects of stiffness coefficient, damping coefficient, time delay, fractional order, and exciting force on the vibration characteristics of roller system are analyzed by comparing the amplitude-frequency curve, time-domain curve and phase diagram. The transition set of the steady-state response of the system and the corresponding bifurcation topology structure are analyzed by using the singularity theory. A magnetorheological fluid damper absorber platform of rolling mill is built based on modern test technology, and the influence laws of the control threshold, control current, type of magnetorheological fluid and reduction rate are analyzed. The correctness and feasibility of the design of the magnetorheological fluid damper absorber are verified, which provided theoretical guidance and technical support for the nonlinear dynamic analysis and stability control of the rolling mill.

Multi-objective optimization design and multi-physics simulation analysis of a novel magnetorheological fluid-elastomer damper

Aiming at the problem of the suspension isolator not being able to adjust the damping, magnetorheological damping technology was introduced based on the traditional rubber passive suspension. A magnetorheological (MR) fluid damper was designed inside the rubber suspension and connected with the rubber structure to form a magnetorheological fluid-elastomer (MRFE) damper. The design principle of the MR damper was described. The principle prototype of the initial MRFE damper was designed, and the mechanical properties of the damper were tested through experiments. Taking the damping force, dynamic adjustable range and power as the optimization objectives, the structure of the MR damper was optimized using the non-dominated sorting genetic algorithm II (NSGA-II). The Pareto optimal solution set of MR damper parameters was obtained, and the structural parameters of the MR damper were determined based on the principle of minimum response time. A multi-physics field simulation model of the optimal damper was established to analyze the dynamic performance of the MR damper. The principle prototype of the optimal MRFE damper was obtained, and the optimal MR damper increased the damping force by 63.1% and the dynamic adjustable range by 104.9% compared with the initial MR damper, while the optimal MRFE damper increased the damping force by 9.27% and the dynamic adjustable range by 8.85% compared with the initial MRFE damper. The design results meet the requirements, and the proposed optimization method can provide a theoretical basis for the optimal design of related vibration-damping equipment.

Semi-Active Suspension Design for Truck Using Pneumatic Spring Joining MR Fluid Damper Based on Neural Networks Controller

<div>In order to modify both stiffness and damping rates according to various road conditions, this research introduces a pneumatic spring in conjunction with a magnetorheological (MR) fluid damper as a single suspension unit for each wheel in the truck. Preventing weight transfer and improving riding comfort during braking, acceleration, and trajectory prediction are the main objectives. A two-axle truck has been used, consisting of three degrees of freedom for the sprung mass, including vertical, pitch, and roll motions, and four degrees of freedom for the unsprung masses, which have been redesigned according to the different types of springs and dampers. Pneumatic-controlled springs, often referred to as dynamic or classic models, replace laminated leaf springs commonly found in vehicles. Additionally, an MR damper replaces a hydraulic double-acting telescopic shock absorber. These models are studied to evaluate the effect of pneumatic spring parameters on truck dynamics. Pneumatic stiffness and the intended damping force are monitored by a recurrent neural network in conjunction with leveling control. This process provides the recommended voltage for the MR damper based on the Signum function damper controller. The performance of the suspension is assessed in the time and frequency domains for both step and random road excitations using vehicle dynamic parameters. Six suspension system configurations are compared with the air spring dynamic model integrated with the MR damper (Model 6), which is recommended as a suspension system for trucks. According to simulation data, when compared to alternative suspension systems, Model 6 significantly enhances both ride comfort and vehicle stability. Model 6 offers improvements in tire workload, truck path, tire–ground contact point during acceleration, braking efficiency, and stopping distance. Compared to previous controlled models, Model 6 also demonstrates zero steady-state offset and zero steady-state error.</div>

Dynamic characteristics analysis and vibration control of coupled bending-torsional system for axial flow hydraulic generating set

Aiming at the vibration problems of shaft system for axial flow hydraulic generating sets caused by complex excitations, the coupled bending-torsional dynamic equations of rotor-runner system are established considering multi-effect including hydraulic, mechanical, electrical and other external vibration sources. Whether taking the torsional degree of freedom into account, the stability and disparate destabilization laws of system periodic solutions are analyzed using the shooting method combined with Floquet theory. On this basis, the influence of coupling bending-torsional effect on system dynamic behaviors is discussed through bifurcation diagrams, Poincaré maps, trajectories, time domains and frequency spectrums. Furthermore, in order to alleviate the unsteady vibration of rotor as well as runner, the magnetorheological fluid damper is introduced into the shaft system, and numerical simulations are performed on models of coupled bending-torsional systems with or without the magnetorheological fluid damper. The analyses indicate that the interaction between bending and torsional vibration of the shaft system will expand the chaotic sustained range for rotor. Meanwhile, the amplitude of the rotor-runner system is magnified owing to the torsional vibration, which leads to local rubbing faults of the system under specific operating conditions, while the intervention of the magnetorheological fluid damper can significantly suppress the nonlinear motion of rotor and runner, reduce the amplitude of system vibration, so as to avoid the occurrence of friction defects effectively. The above research results can provide conducive references for fault diagnosis, optimized design, and vibration control of axial flow hydraulic generating sets.

Performance Analysis of an Induction Motor Coupled VIF with MR Fluid Damper

Performance Analysis of an Induction Motor Coupled VIF with MR Fluid Damper

Investigations of Sustainable Biodegradable Oil and Magnetic Particle‐Based Magnetorheological Fluid Dampers for Vibration Attenuation of a Rotor Dynamic System

This article aims to study the physical characterization and performance of a material‐based magnetorheological fluid (MRF) dampers for vibration attenuation of a high‐speed rotor–motor system near resonance. Four samples are synthesized by combining electrolytic iron and carbonyl iron (CI) with Castor and Karanja oil and experimentally investigated for their contribution to vibration attenuation. The results demonstrate effective vibration attenuation of the biodegradable oil‐based MRF damper than the nonbiodegradable oil‐based MRF damper. The best vibration attenuation is observed in the case of moderately viscous MRF. CI‐based samples exhibit a lower sedimentation rate, hence recommended for MRF. The vibration amplitude is maximum for the Castor oil‐based MRF damper, however, is minimum for the Karanja oil‐based MRF damper. The steady and transient results of vibration amplitudes are obtained and analyzed for different currents supplied to the MRF damper. The range of unstable speed near resonance is also obtained. The prepared samples show higher attenuation of 6–25% than Sample 5. The vibration amplitude attenuation of Sample 4 and Sample 5 are 47% and 22%, respectively. The findings of this study carry significant implications for controlling the vibration of the dynamic system using an eco‐friendly damping system.

Development of a Prandtl-Ishlinskii hysteresis model for a large capacity magnetorheological fluid damper

Magnetorheological (MR) fluid (MRF) dampers, serving as fail-safe semi-active devices, exhibit nonlinear hysteresis characteristics, emphasizing the necessity for accurate modeling to formulate effective control strategies in smart systems. This paper introduces a novel stop operator-based Prandtl-Ishlinskii (PI) model, featuring a reduced parameter set (seven), designed to estimate the nonlinear hysteresis properties of a large-scale bypass MRF damper with variable stiffness capabilities under varying applied current. With only seven parameters, the model realizes current, displacement, and rate dependencies. The force-displacement and force-velocity responses of the designed MRF damper were experimentally characterized under broad ranges of applied current (0–2 A), excitation frequency (0.5–4 Hz), and displacement amplitude (1–2.5 mm). A training dataset was subsequently used to develop a novel field-dependent modified PI model, incorporating multiple hysteresis operators with and without a friction element. The proposed model accurately predicted the MRF damper behavior within the training dataset, and its validity was assessed against data from diverse experimental conditions. The PI model with friction element generally outperformed the model without friction when frequency exceeds 0.5 Hz, demonstrating its ability to characterize nonlinear hysteresis force-displacement and force-velocity properties of the MRF damper under the ranges of applied current and excitations considered with reasonable accuracy. Experimental data were also estimated by the Bouc–Wen model, and compared with those obtained via the formulated PI model, affirming the overall superiority of the proposed PI models considering the computational cost, and total number of parameters. Leveraging the simplicity, minimal parameter requirements, and analytic invertibility of PI models, the proposed PI model is considered a superior choice for modeling and subsequently controlling smart structures employing MRF dampers.

Semi-active control of tool vibration in hard turning using magnetorheological fluid damper

Semi-active control of tool vibration in hard turning using magnetorheological fluid damper

New bell plate controlled multi-inertia channel magnetorheological fluid mount wide frequency vibration isolation control study

This paper introduces a novel type of magnetorheological fluid (MRF) mount designed to achieve wide-frequency vibration isolation for engines. While previous studies have explored vibration isolation using hydraulic mounts, there has been limited research on achieving wideband isolation with MRF mounts. Consequently, this paper presents an innovative MRF mount structure and investigates wideband vibration isolation control for engines. Initially, experiments with a multi-channel MRF damper validate the switchable operation of controllable channels. A novel controllable multi-inertia channel MRF mount system is proposed, aligning the working mode of controllable inertia channels with that of the MRF damper. The lumped parameter method is employed to derive the mathematical model of the MRF mount, and its high and low-frequency dynamic characteristics are thoroughly examined. Subsequently, a real-time multi-island genetic algorithm-optimized controller is developed to investigate wideband vibration isolation within the MRF mount system. The findings indicate that: (1) The MRF mount demonstrates adjustable low-frequency dynamic stiffness and loss angle within the frequency range of f = 0–50 Hz. In the frequency range of f = 50–100 Hz, the mount achieves its lowest dynamic stiffness value, effectively addressing the issue of high-frequency stiffening. (2) The real-time multi-island genetic optimized controller exhibits superior vibration isolation performance compared to traditional sky-hook control and hybrid sky-hook control methods, achieving optimal vibration isolation for the mount.

Semiactive Control of Nonlinear Parametric Vibration of Super‐Long Stay Cable in Cable‐Stayed Bridge Installed with Magnetorheological Fluid Damper

As the stay cables of cable‐stayed bridges become longer, parametric resonance with a large amplitude is more easily triggered, which becomes a vibration hazard of super‐long stay cables. An increasing number of practical applications of vibration mitigation on stay cables demonstrate that vibration control strategies can effectively facilitate hazard mitigation and improve cable‐stayed bridge reliability and service life. This study proposes a semiactive control approach to reduce the parametric vibration of super‐long stay cables in cable‐stayed bridges installed with magnetorheological fluid damper (MRFD). First, using the cable’s gravity sag curve equation, an equation governing the combined stay cable‐bridge deck‐damper control system was established to consider the effect of the chordwise force of cable gravity. Subsequently, a targeted LQR‐based optimal active control law is proposed to provide the target control force in the semiactive control. The parametric influences on the performance of the LQR‐based optimal active control were analysed to provide insight into the proposed control strategy. Since the semiactive control could achieve almost the same control efficacy of the targeted optimal active control, a semiactive control strategy employing MRFD is proposed to mitigate the parametric vibration of a super‐long stay cable. Based on the proposed semiactive control strategy, the system was attached with the MRFD of the longest cable, S36, in the designed prototype long cable‐stayed bridge. The efficacy of the established semiactive control system was also analysed. The analysis results confirm that the proposed semiactive control strategy and designed semiactive control system can perform similar to the LQR‐based optimal active control. The semiactive control system attached to the MRFD can mitigate the parametric vibration of super‐long stay cables in cable‐stayed bridge engineering practice.

Design of Magnetorheological Fluid Damper with Optimal Damping Force

This article focuses on designing and analyzing of an optimal Magnetorheological Fluid Damper (MRFD) having varying piston shape channeled into the piston of the MRFD. A finite element approach has been employed to investigate the impact of piston material, piston shape, MR fluid gap and pole length on the generated magnetic field density, yield stress along with damping force. Taguchi L18 orthogonal array has been exercised to obtain the optimal damping force. The Analysis of Variance (ANOVA) results investigate the contribution of the selected parameters and depict that the MR fluid gap is the most predominant factor which affects the damping force, making a contribution of 77.56%, followed by piston material which contributes 12.40%, pole length with a contribution of 8.23% and piston shape has negligible contribution of 0.07%. Taguchi predicts the optimized model for the selected parameters as A2B2C1D3 which has been validated by carrying out the analysis using ANSYS Maxwell software v. 16. The damping force of 1053 N has been obtained for the optimal MR damper model which is based on the prediction of the Taguchi results.

Neural Network-Based Adaptive Height Tracking Control of Active Air Suspension System with Magnetorheological Fluid Damper Subject to Uncertain Mass and Input Delay.

In this paper, we present a novel robust adaptive neural network-based control framework to address the ride height tracking control problem of active air suspension systems with magnetorheological fluid damper (MRD-AAS) subject to uncertain mass and time-varying input delay. First, a radial basis function neural network (RBFNN) approximator is designed to compensate for unmodeled dynamics of the MRD. Then, a projector-based estimator is developed to estimate uncertain parameter variation (sprung mass). Additionally, to deal with the effect of input delay, a time-delay compensator is integrated in the adaptive control law to enhance the transient response of MRD-AAS system. By introducing a Lyapunov-Krasovskii (LK) functional, both ride height tracking and estimator errors can robustly converge towards the neighborhood of the desired values, achieving uniform ultimate boundness. Finally, comparative simulation results based on a dynamic co-simulator built in AMESim 2021.2 and Matlab/Simulink 2019(b) are given to illustrate the validity of the proposed control framework, showing its effectiveness to operate ride height regulation with MRD-AAS systems accurately and reliably under random road excitations.

Design and Performance of a Compact 3-D-Printed Magnetorheological Fluid Damper

Design and Performance of a Compact 3-D-Printed Magnetorheological Fluid Damper

Thermal-magnetic performance analysis for smart fluid dampers

Abstract Over the years, the Italian Government has taken significant strides in promoting road safety awareness among the students in high schools to create an awareness of prevention and a consciousness of road safety in the student population. In this context, an agreement was signed between the DICEAM Department of the “Mediterranea” University of Reggio Calabria (Italy) and the “Euclide” Higher Education Institute Bova Marina (Italy) to combine road safety with research science in the Science, Technology, Engineering, and Mathematics (STEM) area. With the primary aim of “knowing in order to act”, the students focused on the multi-physics design of magnetorheological fluid dampers as high-performance devices (simple to design and requiring reduced maintenance) for vehicle suspensions, especially class B vehicles. By combining road safety considerations with multi-physics scientific disciplines, the project seeks to emphasize the importance of prevention and knowledge-based action. The study explores the use of magnetorheological fluid dampers, powered by electric current and magnetic induction distribution with thermal loads, to provide appropriate yield stress for developing damping action with repercussions on the quality of road safety. The paper delves into the basic principles of FEM (Finite Element Method) techniques for analyzing an MR damper from both magnetostatic (the main cause generating the damping effect) and thermal perspectives (thermal effects are strongly influenced by environmental conditions). The analysis of an asymmetrical device, where the damping action relies on an MR fluid strip, reveals the significant influence of magnetic and thermal stresses on the magnetization of individual particles and the overall viscosity of the MR fluid.

Comparative study on a single-story RCC frame with large and small-scale magnetorheological damper subjected to seismic excitation

The magnetorheological fluid damper (MRD) is a commonly employed semi-active damping mechanism. The utilisation of this technology has the potential to mitigate the impact of natural hazards on structures, owing to its crucial ability to dissipate energy and its minimal energy consumption. This study aims to compare the performance of a reduced-scale reinforced concrete (RCC) frame with a large MR damper (MRD) attached diagonally, to that of an RCC frame with a smaller-scale MRD attached at different locations. The experimental evaluation of two frames was conducted utilising El-Centro time history data, which was obtained from MTS. The efficacy of the small-scale MRD was also assessed through the El Centro seismic loading before integrating to the RCC frame. Subsequently, it was integrated with the frame and exhibited effective performance in mitigating seismic excitation. The maximum force generated was measured at 2.03kN, accompanied by a notable reduction in displacement of 13.24%. The frame equipped with a diagonal damper directly installed at the beam-column joint exhibits load-carrying capacities that are 12.32% and 19.77% lower than those of the frame equipped with a single and double damper, respectively, positioned at a distance of L/3 from the joint. In comparison to a diagonally placed large damper, the implementation of a small-scale magnetorheological damper (MRD) resulted in a reduction of displacements by 7.99% and 17.59% for single and double MRD configurations installed on the frame, respectively. However, this implementation also led to an increase in forces and alterations in crack patterns. The experimental findings indicate that the inclusion of a substantial quantity of smaller MRD can be a viable approach to mitigating structural responses in regions prone to seismic activity, while still maintaining the aesthetic integrity of the structure.

Modelling and Dynamic Analysis of Adaptive Neuro-Fuzzy Inference System-Based Intelligent Control Suspension System for Passenger Rail Vehicles Using Magnetorheological Damper for Improving Ride Index

The ride comfort and safety of passenger rail vehicles depend on the performance of the suspension system in attenuating vibrations induced by track irregularities. This paper investigates the effectiveness of an Adaptive Neuro-Fuzzy Inference System (ANFIS)-based semi-active controlled suspension system using a magnetorheological fluid damper in reducing nonlinear lateral vibrations of a passenger rail vehicle. A complete rail vehicle model is developed, including the carbody, front and rear bogies, and the passive suspension system’s nonlinear stiffness and damping characteristics are considered from experimental data. The passive suspension model is validated through experiments, and an ANFIS-based controller is incorporated with the secondary vertical suspension system to improve ride behavior. Three semi-active suspension strategies are considered under varying speeds and track irregularities, and their effectiveness is compared to the nonlinear passive suspension system in terms of rms acceleration, rms displacement, ride quality, and comfort. The results shows that the ANFIS-based semi-active suspension system with a magnetorheological fluid damper outperforms the passive suspension system and semi-active strategies in all tested conditions. There is a reduction in rms acceleration by approximately 11.11% to 23.64% and rms displacement by about 5.36% to 32.06%. Moreover, it significantly improves ride quality (9.20% to 31.02%) and comfort (9.96% to 31.50%). The rms acceleration and displacement are reduced, and the Sperling ride index and Percentage Reduction Index values demonstrate that the ANFIS-based semi-active suspension effectively minimizes the impact of rail irregularities and vibrations, resulting in a significant gain in ride quality and passenger comfort.

Study on the Influence of Synthesized Nano Ferrite Powder and Micron Ferrite Powder on Damping of a Single Degree of Freedom System

Magneto Rheological Fluid (MRF) damper has been opted as a promising semi active element of advanced suspension system. This work focuses on the damping nature of magnetorheological fluid under the influence of a magnetic field strength, size and shape of the of the iron oxide particles. A reduced scale single degree of freedom quarter car model with two stage magnetorheological damper, viscosity measurement setup, synthesized and commercially available Fe2O3 powders are used for the experimental study. An air cooled electro-dynamic shaker, Data acquisition system, accelerometers and the Lab view software acquires and analyzes the response of the quarter car model. X-ray Diffraction and Scanning electron microscopy characterize the morphology of iron oxide particles. The vertical acceleration, the displacement, the transmissibility ratio and the damping characteristics are analyzed based on the response of the top plate at different frequencies of base excitation. The results show that the magnetorheological fluid made with nano iron oxide powder has better damping characteristics than that of micron sized iron oxide powder

Design of energy harvesting magneto-rheological fluid damper for vehicle

Modern vehicles must include dampers in the suspension system in order to absorb vibration energy while driving. Passive dampers have dominated the market for many years. To increase the passenger comfort levels, suspension systems with controlled dampers that can adjust to uneven road profiles are needed. Semi-active suspensions have emerged as one of the most popular modern damping solution types due to their ability to manage damping force. The semi-active suspension system of the car uses magneto-rheological (MR) dampers for vibration control. The MR damper consumes low energy, has quick response, and better controllability of the damping force. A part of the energy lost in vehicle dampers can be recovered due to developments in energy-harvesting devices. This regenerated energy can be used in vehicles to power a number of extra systems, such as lighting, heating and air conditioning, and other things. This research attempts to develop an MR fluid damper with energy-harvesting rack and pinion system. The purpose of this study is to design a suspension system that combines an MR fluid damper and an energy-harvesting rack and pinion system. The design calculation involves setting the design parameters for the system that harvests energy and the MR fluid damper. Also, static structural analysis is carried out for both systems using finite element analysis software.