Magnetorheological Damper Research Articles

Experimental Study of Vibration Isolation Using Electromagnetic Damping

This study presents an experimental investigation focused on the reduction of vibrations using electromagnetic damping techniques. The objective is to explore the effectiveness of electromagnetic damping in mitigating undesirable vibrations and enhancing system stability. A single-degree vertically constrained spring-mass system, two pairs of electromagnets, Lab VIEW software, an accelerometer, DAQ card were used for the experimentation. SWG 17 and SWG19 coil electromagnets were used in different conditions of energization to evaluate the effectiveness of the electromagnetic damping system. The parameters such as excitation frequency, vibration amplitude, and electromagnetic damping force are systematically varied and their effects on vibration isolation are analysed. The results demonstrate that the electromagnetic damping system effectively isolates base induced vibrations across a range of frequencies and amplitudes. The experimental data reveal that at lower frequencies, upto 6Hz the amplitude of RMS acceleration was same as that of the system without energizing the electromagnet and at higher frequencies, above 10 Hz, all 2V,4V and 6V of energized electromagnets in the SDVC system showed negligible variation in the RMS amplitude of acceleration. A substantial isolation of top plate was observed at higher frequencies of base excitation.
 

A New Rotary Magnetorheological Damper for a Semi-Active Suspension System of Low-Floor Vehicles

This study explores the significance of active suspension systems for vehicles with lower chassis compared to conventional ones, aiming at the development of future automobiles. Conventional linear MR (magnetorheological) dampers were found inadequate in ensuring sufficient vibration control because the vehicle’s chassis becomes lowered in the unmanned vehicles or purposed-based vehicles. As an alternative, a rotary type of MR damper is proposed in this work. The proposed damper is designed based on prespecified design parameters through mathematical modeling and magnetic field analyses. Subsequently, a prototype of the rotary MR damper identical to the design is fabricated, and effectiveness is shown through experimental investigations. In configuring the experiments, a proportional-integral (PI) controller is employed for current control to reduce the response time of the damper. The results presented in this work provide useful guidelines to develop a new type of MR damper applicable to various types of future vehicles’ suspension systems with low distance from the tire to the body floor.

A smart structural optimization method of magnetorheological damper for ultra-precision machine tool

To address the problem of multi-source vibration in ultra-precision machine tools, a vibration reduction stand was designed by replacing passive damping components with magnetorheological dampers (MRDs). In this work, the structural parameters of MRDs were optimized using an improved pelican optimization algorithm (IPOA) to realize the maximum capability in reducing vibration. Firstly, the working principle of MRDs was explained, and the mathematical models of MRDs were established. Then, an IPOA based on singer chaotic mapping, nonlinear inertia weight factor, and Cauchy mutation strategy was proposed to enhance the global search capability and convergence efficiency of the algorithm. Subsequently, the IPOA was applied to optimize key structural parameters of MRDs, including output damping force, controllable damping range, response time, and power consumption. Finally, COMSOL Multiphysics software was used to verify the effectiveness of the proposed algorithm by comparing the magnetic induction intensity distribution of MRDs before and after optimization, as well as the variation of the four performance indexes under the different applied currents. After being optimized using the proposed IPOA, the MRDs can deliver a larger maximum damping force and a wider damping controllable range, with less power consumption and quick response, which could meet the requirement for vibration suppression of ultra-precision machine tools.

Study on operational temperature of magneto-rheological fluid and design dimensions of magneto-rheological damper for optimization

This study aims to restrict the upper limit for flow gap and effective length in magnetorheological (MR) damper for optimal performance. Initially, the sedimentation study of in-house MR fluid (25%) shows that an 8% reduction in the sedimentation ratio with the addition of additive and nonlinear Herschel-Bulkley (HB) model fit reflects a 32.5% decrease in average yield stress with increasing currents when the parallel plate gap is increased from 1 mm to 2 mm. Owing to this decrease in yield stress, further study is extended to fabricate two MR dampers with limit values (LV) of flow gap and effective length with a common magnetic outer cylinder. Testing results of MR dampers revealed a 72% reduction in damping force at 0.8 A current when the LV’s is increased from LV-1 to LV-2. Selecting LV-1 over LV-2 as the upper limit for any design optimization will give the MR damper optimal performance. At higher input parameters, amplitude has a 135% greater impact on damping force than frequency and current. It is also demonstrated that saturation magnetization depends on the applied magnetic field and input loading parameters. Finally, gravimetric analysis shows that the effectiveness of the MR fluid and magnetic particle starts to decline after 322 °C and 400 °C.

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

Evaluating the impact of electromagnetic effects on randomized and pre-structured smart silicone magneto-rheological damper in hardened steel turning operations

Evaluating the impact of electromagnetic effects on randomized and pre-structured smart silicone magneto-rheological damper in hardened steel turning operations

Fabrication and characterization of graphene oxide (GO)-modified micro-nano composite magnetic microspheres

Addressing the contradiction between the magneto-rheological properties and dispersion stability of MRFs poses a significant challenge in the preparation process. This paper proposes a micro-nano composite material design scheme using graphene oxide as a grafting agent to encapsulate nanoscale magnetite (Fe3O4) particles onto the surface of carbonyl iron powders. The prepared micro-nano composite magnetic microspheres achieve a reduction in density for enhanced stability while ensuring no compromise in magnetic performance. The effectiveness of the preparation process is ensured through the analysis of the microscopic morphology, crystal structure, and elemental characteristics of all process products using Field Emission Scanning Electron Microscopy (FE-SEM), powder X-ray diffraction (XRD), Raman Spectroscopy, and Fourier Transform Infrared Spectroscopy (FTIR). To obtain MRFs more suitable for magneto-rheological damper applications, this study synthesized micro-nano composite MRFs with different base liquids and varying volume fractions. The stability and magneto-rheological properties of each sample were analyzed through visual techniques and rheological testing platforms. The results indicated that micro-nano composite MRFs based on 40% to 50% silicone oil exhibit superior stability in various aspects, including sedimentation stability, redispersion stability, and temperature stability. Additionally, the micro-nano composite MRFs demonstrated significantly enhanced magnetic performance compared to pure micrometer-sized, pure nanometer-sized, and micro-nano hybrid MRFs.

Augmented Kalman Estimator and Equivalent Replacement Based Taylor Series-LQG Control for a Magnetorheological Semi-Active Suspension

This research presents an augmented Kalman estimator and an equivalent replacement-based Taylor series (ERBTS)-linear quadratic Gaussian (LQG) control strategy to cope with the control accuracy and response delay of magnetorheological (MR) dampers for vehicle semi-active suspensions. The parameters in the MR model are identified from experimental measurements. Then, two main sources of control error, namely, modelling error and real-time variety of the MR damper output force, are defined as an integrated compound real-time variety. Subsequently, they are written into a differential equation with characteristics of the minimum system to augment the state equation of the semi-active suspension system. The augmented Kalman estimator is constructed to estimate the abovementioned compound real-time variety. To calculate an acceptable time-delay compensation predictive control force, an equivalent operation is implemented beforehand in the suspension comprehensive performance index by replacing a part of the squared time-delay control force with the corresponding predictive control force. Simulation results verify the effectiveness of the proposed augmented Kalman estimator, and the newly developed ERBTS-LQG controller almost achieves control effectiveness of the ideal time delay free semi-active suspension.

Vibration control for a semi-submersible floating offshore wind turbine with optimal ultra-low frequency electromagnetic tuned inerter-mass dampers

The platform of a semi-submersible floating offshore wind turbine is prone to large ultra-low frequency pitch motion in a complex marine environment. To address this problem, this study proposes the application of multiple ultra-low frequency electromagnetic tuned inerter-mass dampers (UF-ETIMDs) inside the offset columns to mitigate the pitch motion of the platform. An UF-ETIMD is achieved by replacing the viscous damping of the classical tuned mass damper (TMD) with an electromagnetic inerter damper in series with a tuning spring, which will tune the inerter's resonant frequency. A constant-force spring is added in parallel with the main spring to neutralize the gravity force of the mass damper that can effectively reduce static elongation of the main spring while tuning the resonant frequency of the mass to ultra-low frequency of the pitch motion. Thus UF-ETIMDs can achieve a double-tuned electromagnetic damping system to enhance the vibration mitigation performance of the platform. The parametric optimization of the UF-ETIMDs is conducted based on the H∞ optimization criteria, whose target is to minimize the peak value of platform pitch in the frequency domain. To analyze the performance of the UF-ETIMD on the semi-submersible FOWT, a 20-degree-of-freedom (DOF) analytical model has been developed for the semi-submersible FOWT coupled with three UF-ETIMDs, retrofittable inside the platform. The performance of the UF-ETIMDs is examined and compared with the classical TMDs under different combinations of wind and wave loadings and in both operational and parked conditions. Results found that UF-ETIMDs can achieve a better performance than TMDs in mitigating the platform pitch of the semi-submersible FOWT. The potential powers in the UF-ETIMDs system that could be converted from vibrations to usable electricity are also examined.

Research on Mechanical Leg Structure Design and Control System of Lower Limb Exoskeleton Rehabilitation Robot Based on Magnetorheological Variable Stiffness and Damping Actuator

During the walking process of lower limb exoskeleton rehabilitation robots, inevitable collision impacts will occur when the swinging leg lands on the ground. The impact reaction force from the ground will induce vibrations in the entire robot’s body from bottom to top. To address this phenomenon, considering the limitations of traditional active compliance and passive compliance methods, a variable stiffness and damping actuator (VSDA) leg structure using a magnetorheological damper (MRD) is proposed. Firstly, experimental methods are used to obtain the ground reaction force (GRF) exerted on a normal person during walking. Then, a mathematical model of the VSDA leg structure is constructed, and its working principle is analyzed. Based on human mass and dimensions, a 3D model is designed and selected. Finally, a simulation model is built in the MATLAB/Simulink environment using the fuzzy switch damping control strategy to simulate the acceleration and displacement of the human body under sinusoidal and random excitations. The results indicate that under sinusoidal excitation, employing fuzzy switch damping control optimizes human displacement by 72.47% compared to the high stiffness and high damping system, and by 16.95% compared to the switch damping system. Human acceleration is optimized by 52.09% compared to the high stiffness and high damping system, and by 25.2% compared to the switch damping system. Under random excitation, adopting fuzzy switch damping control optimizes human displacement by 59.09% compared to the high stiffness and high damping system, and by 21.74% compared to the switch damping system. Human acceleration is optimized by 78.74% compared to the high stiffness and high damping system, and by 31.66% compared to the switch damping system. This validates the VSDA design structure and control method, demonstrating certain advantages in improving the compliance and stability of lower limb exoskeleton rehabilitation robots.

An invertible hysteresis model for magnetorheological damper with improved adaption capability in frequency and amplitude

It is found during the tests that the damping characteristics of the magnetorheological (MR) damper vary with the excitation amplitude and frequency. However, the existing MR damper models are not able to accommodate the change of excitation amplitude and frequency, which will lead to significant modeling errors. To deal with this problem, this paper analyzes the experimental data and obtains the regularity of the damping characteristics varying with the excitation. Subsequently, an excitation-adaptive MR damper model is constructed based on the hyperbolic tangent function. The proposed model is not only able to adapt to the change of excitation amplitude and frequency but also able to inverse, which is essential for MR damper controller construction. The fitting results show that compared with the existing models, the three normalized errors of the proposed model are improved from 22.61%, 13.96%, and 19.42%–6.30%, 3.81%, and 6.97%, respectively, indicating that the model excitation adaptivity is significantly improved. Furthermore, this study also proposed a damper controller based on the new model, and the simulation results verify the effectiveness of the controller. The proposed model brings the acceleration signal into the model to improve the model adaptivity, which introduces a novel approach to enhance the adaptivity of MR damper models.

Design and experimental analysis of magneto-rheological damper featuring a labyrinthic dual-channel valve

For the sake of improving the damping performance of the cab suspension system, the MR damper featuring the labyrinthic dual-channel valve (LDCV-MRD for short) is proposed in this paper, which is composed of a mixture of circular channel, circular disk channel and circular tube channel. The LDCV-MRD is designed structurally and the magnetic circuit is analyzed. The output damping force mathematical model is established, and the coil’s number of turns is computed. The magnetic field in the damping channel of LDCV-MRD is simulated and analyzed. The processed and fabricated LDCV-MRD is tested, and the experimental results are compared and analyzed with the simulation results. The results show that the simulated values of the maximum damping force and the adjustable coefficient fit well with the experimental results. The peak output damping force of the experiment achieves 21 008 N. The adjustable coefficient reaches about 5.61, when the input current gets to 2 A.

H hybrid control and MRD in a steel frame building subjected to excessive vibrations caused by the dynamic action of wind and earthquake

The dynamic loads from earthquakes and winds can destroy lives, cause collapse in civil structures, and interrupt basic services provided to the population. In this scenario, structural designs must be developed to decrease the damage induced by these actions. The objective of this work is to design a hybrid controller based on the H¥ optimization via state feedback and the magneto-rheological damper (MRD) to mitigate the excessive vibrations of a three-story steel frame building, represented through the shear building model, subjected to the simultaneous dynamic action of wind and earthquake. All research is based on computational simulation, experimental research and results will not be addressed. In the numerical analysis, digital computer and MATLAB® software are used, and implemented codes generate the expected results based on the mathematical modeling. With the application of the H¥ control technique via state feedback, the displacements were reduced by 77%. With MRD this reduction was 79%. With the hybrid controller, this reduction was 100%. Thus, the verifications in relation to maximum displacements were met for NBR 15421:2006, NBR 8800:2008 and NBR 6118:2014. From the results, it is concluded that the hybrid controller proved to be more efficient and achieved the proposed objective. The exogenous inputs had zero influence on the behavior of the system output.

A novel method of suppressing machining vibration in robotic milling using magneto-rheological foam damper

Owing to their remarkable flexibility and favorable cost-effectiveness, industrial robots have found extensive applications to cutting of materials across sophisticated manufacturing fields. However, the structurally low rigidity of these robots renders the tool tip prone to substantial oscillations during machining processes, significantly impacting product fabrication quality. The objective of this study is to present a novel methodology employing magnetorheological dampers for mitigating vibrations during robotic milling operations. Specifically, a new type of ring nested Magneto-Rheological Foam Damper (MRFD) working in the squeeze mode is developed. Firstly, the MRFD's structure is designed considering the vibrational characteristics of robotic milling. Subsequently, a damping force model of the MRFD is derived. The feasibility of the MRFD’s structural design is validated by the finite element analyses, which is instrumental in comprehending the influence of structural parameters on the electromagnetic characteristics of the MRFD. Next, a prototype of the MRFD is fabricated selecting appropriate parameters. Finally, a series of excitation and milling experiments are conducted on a KUKA KR500 robot. The outcomes demonstrate a substantial reduction (37%-69%) in radial vibration amplitude at the tool tip during robotic milling, highlighting the effectiveness of the developed MRFD. This research endeavor has introduced a pioneering avenue and framework for vibration control in robotic milling, offering a novel paradigm for enhancing the precision of robotic machining.

Seismic control of multi-degrees-of-freedom structures by vertical mass isolation method using MR dampers

Seismic control of multi-degrees-of-freedom structures by vertical mass isolation method using MR dampers

Enhanced ship engine vibration reduction using magnetorheological dampers and Adaptive Neuro-Fuzzy Control System

ABSTRACT In this paper, an innovative approach is proposed to mitigate ship engine vibrations by integrating a semi-active control system with magnetorheological (MR) dampers and an Adaptive Neuro-Fuzzy Control System (ANFIS). The ANFIS controller adjusts MR damper damping force to effectively adapt to engine vibrations. A comprehensive mathematical model simulates the complex dynamics of the ship engine vibration system, validated with real-world data. The model incorporates engine vibration measurements and MR damper properties to train the ANFIS controller. Compared to passive control systems, the proposed semi-active system reduces torsional vibrations by 22.606% and longitudinal vibrations by 29.840%. The ANFIS controller dynamically adjusts damping force in response to engine conditions, ensuring optimal performance. This system effectively mitigates ship engine vibrations, improving overall ship performance and passenger comfort. Consistency between modeling and experimental results confirms the system's viability and efficacy.

Modeling and optimization of car suspension system in the presence of magnetorheological damper using Simulink-PSO hybrid technique

The suspension system is one of the important parts of the vehicle, which plays a substantial role in the steering and comfort characteristics of it. In the present research work, the optimization of the suspension system parameters has been carried out with the aim of reducing the vehicle vibrations. In this study, the magnetorheological damper (MR damper) is added to the one-half car model with four degrees of freedom and the effects of improving the efficiency of the suspension system have been investigated. In order to model the vehicle system, MATLAB/Simulink software is employed. The particle swarm optimization (PSO) algorithm has been applied to optimize the variables of the suspension system in order to decrease the vehicle vibrations and passenger comfort. The optimization of suspension system variables has been done for two bond-limited white noise and sinusoidal wave inputs. The outcomes revealed that the addition of MR damper in any mode reduces the vehicle vibrations. The maximum reduction in the vehicle vibrations was related to the state where all the variables of the suspension system were optimized and the amount of the objective function in that state was improved by about 32%.

Multi-Physical Field Simulation of Magnetorheological Fluid Flow State in Valve Magnetorheological Damper

Magnetorheological fluid (MRF) is a kind of magnetic field responsive intelligent fluid, which is widely concerned in the field of damping and vibration reduction. The flow state of MRF plays a key role in vibration control in dampers. In this work, the flow behavior. of magnetorheological fluid (MRF) in a valve damper is studied through multi-physical field simulations. The objective is to comprehensively comprehend the influence of the magnetic field on the velocity distribution and pressure drop of the MRF within the damper channel. The magnetic field is generated by creating an electrified coil, and the magnetic flux density is subsequently changed by adjusting the current. The magnetic field calculation shows that the magnetic field is almost perpendicular to the MRF flow direction at the narrowest part of the damper channel. Next, based on the coupling calculation of multiple physical fields between fluid flow, electric field, and magnetic field, the flow velocity and pressure characteristics of MRF in the flow channel were calculated and analyzed. The results indicate that at the slit where the MRF flow direction is perpendicular to the magnetic field direction, the volume force acting on the MRF reduces its flow velocity, resulting in a significant pressure difference between the left and right sides of the flow channel. Additionally, the flow rate of MRF exhibits a decrease as the magnetic field strength increases. When the magnetic field strength increases from 0. 5T to 1. 5T, the flow rate of MRF fluid at the narrowest part of the flow channel decreases by about 0. 18m/s.

Mathematical Analysis of the Electromotive Induced Force in a Magnetically Damped Suspension

This study explores the advanced mathematical modeling of electromagnetic energy harvesting in vehicle suspension systems, addressing the pressing need for sustainable transportation and improved energy efficiency. We focus on the complex challenge posed by the non-linear behavior of magnetic flux in relation to displacement, a critical aspect often overlooked in conventional approaches. Utilizing Taylor expansion and Fourier analysis, we dissect the intricate relationship between oscillation and electromagnetic damping, crucial for optimizing energy recovery. Our rigorous mathematical methodology enables the precise calculation of the average power per cycle and unit mass, providing a robust metric for evaluating the effectiveness of energy harvesting. Further, the study extends to the practical application in a combined system of passive and electromagnetic suspension, demonstrating the real-world viability of our theoretical findings. This research not only offers a comprehensive solution for enhancing vehicle efficiency through advanced suspension systems but also sets a precedent for the integration of complex mathematical techniques in solving real-world engineering challenges, contributing significantly to the future of energy-efficient automotive technologies. The cases reviewed in this article and listed as references are those commonly found in the literature.

Semi-Active Groundhook Control of Offshore Tension Leg Platforms Using Tuned Mass Damper With Optimized Parameters and Magneto-Rheological Damper Under Multiple Hazards

Abstract The purpose of the current study is to recommend an offshore tension leg platform (TLP) semi-active control system to lessen vibrations caused by various risks, such as the wind load and regular and irregular waves. State-of-the-art indicates that there has not been much study on semi-active management of offshore TLPs exposed to numerous hazards while taking into account system nonlinearities and employing a control method that is resilient to uncertainty. An augmented velocity–displacement-based groundhook (AVDB-GH) semi-active control scheme using magneto-rheological (MR) dampers, which is an improvement over the displacement-based groundhook (DB-GH) control algorithm, is proposed. The proposed controller uses a semi-active tuned mass damper (SATMD) consisting of a passive tuned mass damper (TMD) and two semi-active MR dampers as the control devices. Constrained nonlinear optimization is used to determine the SATMD's optimized parameters in order to produce the best control performance. A significant reduction in surge response of TLP is observed both in the time domain and the frequency domain. Compared to the SATMD using the usual DB-GH algorithm, the suggested control strategy more successfully decreases the key response variables—deck displacement, power spectral density, and acceleration. The effectiveness of the controller is better for regular waves than for irregular waves and wind forces. Because the performance of the controller is unaffected by changes in the mass and stiffness of the TLP, the controller can be regarded as robust.