Magnetorheological Fluid Damper Research Articles

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.

Experimental investigation into the effect of magnetorheological fluid damper on vibration and chatter in straight turning process

Magneto-Rheological (MR) dampers have received a great deal of attention in recent years due to the potential of offering semi-active control. MR dampers have been successfully applied in the vibration control of several machining processes. However, the effect of the material of the damper's fluid chamber on its magnetic properties has not been studied much. In this study, an MR damper has been designed to control the chatter vibration of the straight turning operation. The magnetic properties of the MR damper are simulated in the FEM software COMSOL Multiphysics with two types of steel AISI 410 and AISI 1018, and the material with the best performance for constructing the fluid chamber is determined. Then, the MR damper with an assembly to hold the cutting tool was fabricated and experimentally tested during straight turning operation and its effect on the tool vibration, and work surface roughness was analyzed. From the result, it was observed that the MR damper reduced tool vibration and chatter effectively. The results obtained in this research confirm that the application of the MR damper in the straight-turning process can either suppress the chatter or greatly reduce the frequency amplitude of the chatter. The reduction of the tool's acceleration amplitude with the MR damper was more intense in the condition of chatter suppression and reached up to 89.42 %. Moreover, the MR damper reduced the roughness of the machining surface. This reduction was higher in cases where the chatter was suppressed and it was observed up to 29 %.

Development of a new dynamic hysteresis model for magnetorheological dampers with annular-radial gaps considering fluid inertia and compressibility

Modeling the inherent non-linear dynamic hysteresis behavior of magnetorheological (MR) fluid dampers is a fundamental necessity for their practical implementation. Quasi-static models, have been developed under very low frequency and small amplitude excitation conditions, are only beneficial in the early stages of MR dampers design and are sufficient for manufacturing requirements. These models, however, have failed to predict the non-linear hysteresis behavior of MR dampers (i.e., force-displacement and force-velocity characteristics) under low to moderate ranges of frequency and displacement amplitudes. The main contribution of the present work is to formulate a novel physic-based dynamic model to predict the non-linear behavior of MR dampers featuring an annular-radial bypass valve under different applied currents, and low to moderate input excitations. The proposed model incorporates unsteady fluid behavior and the fluid compressibility effect on the hysteretic response without relying on experimental data to evaluate the model parameters. To derive the model, the velocity profile and the pressure drop have been derived by solving the fluid momentum equation via the Laplace transform technique and Cauchy residue theory. The continuity equation has been employed for considering the compressibility contribution to hysteretic response based on the variation of bulk moduli. The predicted results for the force-displacement and force-velocity behavior of the MR damper were subsequently compared with the experimental results. Results suggest the effectiveness of the proposed model for predicting the dynamic hysteresis characteristics of the annular-radial MR fluid dampers under the relatively sufficient variation of mechanical and magnetic loading conditions considered.

Experimental and numerical study of the forward and inverse models of an MR gel damper using a GA-optimized neural network

In this paper, we present a series of experimental and numerical studies on the performance and modeling of a developed magnetorheological gel (MRG) damper. A bi-directional shear-type damper was designed and fabricated. The MRG damper, which utilizes the gel’s high viscosity, can effectively alleviate the settlement problem inherent in magnetorheological fluid damper applications. Then, dynamic performance experiments were carried out to obtain the damping force with sinusoidal and random displacement excitations. Based on the test results, the forward model of the damper was established using a backpropagation neural network. A genetic algorithm was employed to optimize both the network structure parameters and the initial weight and bias values. Different forward models generated using different training datasets were validated and compared with the RBFNN model and Bouc-Wen model using different test datasets. The validation results indicate that the neural network-based forward model greatly outperforms the RBFNN model and Bouc-Wen model in terms of the estimation performance. The influence of the inputs at previous time has also been investigated. Finally, to generate the command current for controlling the damper, inverse neural network models with optimized structure parameters were established using different training datasets. Validation results with different test datasets indicate that, although the predicted current generated by the inverse models has many high-frequency components, it can still act as an effective damper controller, with the resulting damping force calculated using the predicted current coinciding well with the desired behavior.

The stability analysis and nonlinear vibration control of shaft system for hydraulic generating set under multi-source excitation considering effects of dynamic and static eccentricities

Aiming at nonlinear vibration problems of shaft system for hydraulic generating set caused by multi-source excitation, based on the construction of unbalanced magnetic pull considering dynamic and static eccentricities, a coupled bending–torsional vibration model of shaft system and corresponding differential equations under the action of multi-vibration sources are established. Nonlinear dynamic analysis is conducted by the shooting method, and the Floquet theory is applied to investigate the stability of system periodic solution. On this basis, discrepancies of dynamic characteristics for systems whether mixed eccentricities are excluded are compared, disclosing that dynamic features of system change dramatically when composited eccentricities are taken into account, and effects from mass eccentricity, excitation current, as well as static and dynamic eccentricities on oscillation response of system are revealed thoroughly by means of numerical method. The magnetorheological fluid damper is incorporated into the system for the purpose of suppressing the nonlinear vibration during operation, and corresponding suppression laws on vibration of rotor and runner are disclosed. While reducing the amplitude of system, fixed eccentricities also increasing the probability of chaotic motion, in addition, the new dynamic phenomena including period 3, period 5 and period 6 are revealed. The rotor displacement will be altered by the fluctuation of excitation current, which affects the dynamic response of runner through stiffness item indirectly. The high dissipation capacity of magnetorheological fluid damper can effectively ameliorate the unsteady dynamic response of system, reduce the amplitude and inhibit the irregular movement of rotor and runner to a certain extent, so as to further increase the stability of unit. The relevant research results can provide references for fault diagnosis and vibration control of hydraulic generating set, as well as for the optimal design.