Magnetorheological Damper Research Articles

Semi‐Active Vibration Control of the Thickening Mill Equipment Based on the MR Damper

The thickening mill equipment installed on the second floor is damage for the structural and personal health. In this study, the vibration conditions of thickening mill equipment and its vibration isolating based on MR damper technology are investigated experimentally and simulacrum. First, the vibration test of thickening mill equipment installed on rigid foundations is operated, and the results show that while the rigid foundation can suppress equipment vibration, it also deteriorates vibration transmission to the ground, which results in vibration displacement of the ground exceeds the permissible range by 120%. Second, a MR damper utilized to form the elastic foundation is tested to acquire the force–velocity characteristics, which is described by the proposed Bingham model. The comparison results between the model predicted and measurement data delicate that can effectively describe the correlation between the dynamic properties of MR damper and the coil current/excitation conditions. Finally, an elastic foundation consisting of eight coil springs and several MR dampers is proposed to replace the rigid foundation of the thickening mill equipment. Together with the ON–OFF skyhook control algorithm, the properties of the elastic foundation to reduce the force transmission rates are tested based on the simulation model. The simulation results suggest that the designed elastic foundation can effectively reduce the vibration transmission from the thickening mill equipment to the ground, which can decrease the peak force transmission rate by 95.5%. This study provides a guide to technological transformation methodology of the thickening mill equipment to reduce structural vibration.

A versatile semi-active magnetorheological inerter with energy harvesting and active control capabilities

Semi-active devices typically adjust the system’s damping coefficient to control vibration, offering advantages such as excellent performance and low power consumption. However, the output force of the traditional variable damping (VD) device can only be opposite to the relative motion direction of the device’s two terminals, which limits the vibration control performance. This paper introduces a versatile semi-active magnetorheological (MR) inerter with three operating modes, the VD, energy harvesting, and active control modes, to break through the performance bottleneck of traditional semi-active devices. The MR inerter combines two MR dampers and a flywheel, acting as the controllable units and energy sink. The built prototype is tested, and its parameters are identified. When the innovative semi-active inerter works with a corresponding control strategy to regulate the current in two MR dampers, it can achieve vibration energy storage and release. The harvested energy can help to reduce the high dependency of the semi-active output force on external inputs. The proposed semi-active inerter has excellent potential in the future applications.

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.

Static Output Feedback Control With Damping Curve Adaptation for Semi-Active Suspension With Magneto-Rheological Damper

Static Output Feedback Control With Damping Curve Adaptation for Semi-Active Suspension With Magneto-Rheological Damper

Energy harvesting and inter-floor impact noise control using an optimally tuned hybrid damping system

Impact-loaded floor structures radiate undesired sound waves into adjacent rooms, compromising the acoustic comfort. On the other hand, substantial structural vibrations caused by the impact loading offer a promising energy source for harvesting. Nevertheless, a systematic analytical or numerical investigation of simultaneous inter-floor impact sound transmission control and energy harvesting appears to be missing. Current study describes the conceptual development of a fully coupled 3D analytical model of a dual-functional double-plate floor structure optimized for hybrid regenerative control of inter-floor impact sound transmission. Leveraging multi-mode shunted piezoelectric and Electromagnetic Damper (EMD) energy transduction mechanisms, the model structure is composed of two PZT sandwich plates, which are interlinked through a Nonlinear Vibration Absorber (NVA)-based EMD. The finite Fourier cosine transform and standard normal mode approach are employed to treat the governing acousto-elastic equations. Non-dominated Sorting Genetic Algorithm II is applied to tune the system parameters along Pareto frontiers to target maximum pressure mitigation, maximum energy harvesting, or dual-objective optimization, which hires advantageous features from both configurations for an optimal trade-off between them. Simulations reveal that elasto-acoustic response suppression and energy extraction of the employed stand-alone PZT-based conversion mechanism can be remarkably improved with the adopted optimized hybrid PZT/NVA/EMD-equipped system.

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.

High magnetization composite magnetic fluid: structure, magnetorheology and new sealing mechanism in rotating seals.

The sealing capacity of magnetofluidic (MF) rotating seals is limited by the highest magnetization of the sealing ferrofluids (FFs) of about 1000 G (80 kA m-1). A sharp, almost an order of magnitude, increase in the supported pressure drop is possible by using a magnetorheological (MR) suspension as sealing fluid, owing to the much higher saturation magnetization of MR fluids compared to FFs. However, rotating seals with MR fluids have several shortcomings, such as a significant increase of the friction torque due to the growth of shear stress in the strong magnetic field specific to MF seals and leakage of the non-magnetic carrier liquid. At least partly, these issues can be avoided by using ferrofluid based extremely bidisperse MR suspensions of micrometer-sized iron (Fe) particles dispersed in a ferrofluid, as sealing fluid. The composite Fe3O4-Fe magnetic fluid used in this study consisted of hundreds of nanometers up to few microns size structures of interconnected (welded) Fe nanoparticles (FeMNPs) dispersed in a high colloidal stability ferrofluid with 500 G (40 kA m-1) saturation magnetization. The volume fraction of iron NPs varies from 0.5 to 15% in the ferrofluid carrier which significantly increases the magnetization and simultaneously produces important changes of flow properties in magnetic field of the resulting composite fluid, from Newtonian to strongly non-Newtonian behavior. The evaluation of the magnetic and magnetorheological behavior includes the dependence of magnetization, effective viscosity, magnetoviscous effect and dynamic yield stress on the volume fraction of Fe nanoparticles dispersed in the ferrofluid carrier. The seal gap filled with interconnected Fe nanospheres consists in randomly distributed microregions with a high intensity and high gradient magnetic field that captures the ferrofluid and provides a new sealing mechanism. Already a small amount of interconnected Fe nanospheres additive (2.5-5.0% volume fraction) produces four times increase of the rotating seal burst pressure, a much higher increase than what can be obtained from using a conventional magnetic fluid with the same magnetization. The nano-composite sealing magnetic fluid proved to be a cost-effective solution to significantly increase the performance of multi-stage rotating MF seals.

Newly Developed Current Source Based Shortening and Modeling Methods for Magnetorheological Damper Response Time

Newly Developed Current Source Based Shortening and Modeling Methods for Magnetorheological Damper Response Time

A Review on Modeling and Control of Magnetorheological Dampers

A Review on Modeling and Control of Magnetorheological Dampers

Structural design of composite magnetorheological damper and experimental study on block forming machine

Structural design of composite magnetorheological damper and experimental study on block forming machine

Optimal positioning and distribution of magnetorheological damper

During seismic events, devices are used to disperse energy in buildings, reducing structural damage and preventing collapse. One such device is the magnetically polarizable particle damper, consisting of a hydraulic cylinder filled with magnetically responsive particles in fluid. Recent research optimized damper placement and distribution using detailed mathematical modeling and mode shapes covering over 95% of the building's mass. Researchers identified critical damper positions by correlating these models with maximum force functions in the equations of motion. The study proposed a positioning strategy to reduce costs associated with damper installation in typical building practices. The number of dampers required varied with applied loads: 20kN, 30kN, 90kN, and up to 200kN. For instance, under 20kN and 30kN loads, optimal distribution included assigning 8 dampers to the ground, first, second floors, decreasing to 4 on floors three and four, and 2 on the fifth floor, totaling 14 and 20 dampers, respectively. Optimization values for these loads were calculated at 17.71. Dealing with a 90kN load required 44 dampers, distributed as 8 on lower levels, 4 on the third floor, and 8 each on floors four and five. Remarkably, while 20kN and 30kN damper counts reduced, 24 were added for 90kN, yielding an optimization score of 45.84. For a 200kN load, 17 dampers were strategically allocated, with specific placements adjusted per floor, achieving an efficiency score of 49.616. This underscores the effectiveness of the chosen damper arrangement in bolstering structural resilience against seismic forces.

Theoretical investigation of the rail vehicle suspension system using different optimised controllers by harmony search algorithm incorporating magnetorheological dampers

Theoretical investigation of the rail vehicle suspension system using different optimised controllers by harmony search algorithm incorporating magnetorheological dampers

Design of an Asymmetric Damping Structure for a Single Cylinder and Single Rod MR Damper

Design of an Asymmetric Damping Structure for a Single Cylinder and Single Rod MR Damper

Investigating the Impact of Magnetorheological Suspension on Trajectory Tracking of Autonomous Vehicles

Investigating the Impact of Magnetorheological Suspension on Trajectory Tracking of Autonomous Vehicles

Damping Coefficient Characterization and Experiment of an Electromagnetic Damper for Shimmy Reduction

Damping Coefficient Characterization and Experiment of an Electromagnetic Damper for Shimmy Reduction

A Novel Self-Powered PMSM Electromagnetic Damper Based on Adaptive Economic Model Predictive Control

A Novel Self-Powered PMSM Electromagnetic Damper Based on Adaptive Economic Model Predictive Control

Study of the operation of active suspension with magnetic fluid-less shock absorbers

The article presents the structure of an active suspension system for a commercial vehicle aimed at enhancing system performance. Solutions for integrating electromagnetic dampers into an intelligent active suspension system are identified. The behavior of the suspension system under challenging road conditions is examined. A block diagram of the active suspension system with a controller is provided. The article is published based on the findings of a research project conducted as part of a grant competition for scientific research projects by the teaching staff of Saint Petersburg State University of Architecture and Civil Engineering (SPbGASU) in 2024. Keywords magnetic shock absorbers, electromagnetic shock absorbers, suspension, damping, modeling

Magnetorheological fluids: A comprehensive review

The magnetorheological (MR) fluids contain magnetic micro-sized iron particles, non-magnetic-based fluid, and some additives in order to mitigate sedimentation and agglomeration. The various carrier fluids used in the preparation of MR fluids are mineral oil, silicon oil, castor oil, soybean oil, kerosene, synthetic oils, honge oil, organic oil, water-based oils, etc. However, for obtaining better vibration control, silicone oil is the most preferred one due to its higher viscosity index, lower friction characteristics, higher flash point, and higher shear strength. The MR fluids have various application areas such as dampers, prosthetic knees, valves, brakes, clutches, finishing processes etc. The dampers containing MR fluids are used in automobile cushioning for enhancing passenger comfort and MR suspensions significantly improve steering stability in vehicles. In case of MR brakes, the braking torque on the rotating disks is controlled using the generated shear stress. The carbonyl iron (CI) particles exhibit better rheological characteristics as compared to electrolytic iron (EI) particles. The use of MR fluids produces stable and natural limb movement in orthoses, lower limb prostheses, and exoskeletons. The MR fluids also prove to be very significant in polishing applications. There are various issues with preparation methods and difficulties in the storage of MR fluids. The problems encountered in the synthesis of MR fluids include sedimentation, agglomeration, in-use thickening, corrosion, erosion, etc. The impact of particle proportion, particle shapes, and size has been influential in evaluating MR characteristics. The viscosity and shear stress of MR fluid have been mitigated at higher values of temperature and even CI particles get oxidized at higher temperatures. The CI particles as compared to EI particles are the majority favourable particles used for dispersing state within the MR fluids due to their higher value of saturation magnetization, more availability, and lesser cost. The small-sized particles led to lower wettability, whereas larger-sized particles accounted for an increased sedimentation rate. The currently available MR fluids cost is still on the higher side and the preparation of economical MR fluid is still a big challenge for the researchers. The MR fluids storage is also a big concern. The future scope of MR fluid may be in heavy industries such as nuclear, shipbuilding, oil and gas, space and aviation, etc. to achieve the desired damping response.

Interacting Multiple Model Estimators for Fault Detection in a Magnetorheological Damper.

This paper proposes a novel estimator for the purpose of fault detection and diagnosis. The interacting multiple model (IMM) strategy is effective for estimating the behaviour of systems with multiple operating modes. Each mode corresponds to a distinct mathematical model and is subject to a filtering process. This paper applies various model-based filters in combination with the IMM strategy. One such estimator employs the recently introduced extended sliding innovation filter (ESIF) known as the IMM-ESIF. The ESIF is an extension of the sliding innovation filter for nonlinear systems based on the sliding mode concept. In the presence of modeling uncertainties, the ESIF has been proven to be more robust compared to methods such as the extended Kalman filter (EKF). The novel IMM-ESIF strategy is also compared with the IMM strategy, which incorporates the unscented Kalman filter (UKF), referred to herein as IMM-UKF. While EKF uses Taylor series approximation to linearize the system model, the UKF uses sigma point to calculate the system's mean and covariance. The methods were applied to an experimental magnetorheological (MR) damper setup, which was designed for testing control and estimation theory. Magnetorheological dampers exhibit a diverse array of applications in the automotive and aerospace sectors, with particular relevance to attenuating vibrations through adaptive suspension systems. Applied to a magnetorheological (MR) damper with distinct operating modes determined by the damper's current, the results showcase the effectiveness of IMM-ESIF. In mixed operational conditions, IMM-ESIF demonstrates a notable 80% to 90% reduction in estimation error compared to its counterparts. Furthermore, it exhibits a 4% to 5% enhancement in correctly classifying operational modes, establishing IMM-ESIF as a promising and efficient alternative for adaptive estimation in electromechanical systems. The improved accuracy in estimating the system's behaviour, even amidst uncertainties and mixed operational scenarios, signifies the potential of IMM-ESIF to significantly enhance the overall robustness and efficiency of estimations.

Stochastic Optimization of Electromagnetic Inertial Mass Dampers in Nonlinear Hybrid Base Isolation Systems Under Seismic Excitations

Recently developed inerter-based dampers have been installed at the base layer to reduce base displacement and simultaneously improve the superstructure’s performance. However, in the existing research on optimizing damper parameters, the nonlinear property of base isolation is simplified and stochastic linearization technique is introduced to approximate such nonlinearity, which would inevitably introduce errors. In this paper, an improved method is proposed for stochastic optimization of electromagnetic inertial mass dampers (EIMD) in nonlinear hybrid isolation systems subject to seismic excitations. First, a stochastic seismic excitation is represented by one elementary random variable adopting the dimension-reduction spectral representation method. Then, statistical moments of nonlinear base-isolated structural responses are estimated using two-point estimation method (2PEM). Finally, the EIMD optimal parameters are obtained via the modified directional bat algorithm (MDBA) recently proposed by the authors through minimizing base layer response moments. This proposed improved method could fully consider the base isolation nonlinearity compared with the previous stochastic linearization technique. Moreover, the proposed stochastic optimization of the EIMD only requires two dynamic analyses to achieve its efficiency. A seven-story base-isolated frame building equipped with an EIMD is investigated in the numerical simulation, and results indicate that EIMD optimized by this proposed method obviously outperforms the results by the stochastic linearization technique and the conventional viscous damper (VD) in the base layer displacement reduction.