Vibration control of the engine body of a vehicle utilizing the magnetorheological roll mount and the piezostack right-hand mount

Jeon, Juncheol,Han, Young-Min,Lee, Dong-Young,Choi, Seung-Bok SAGE Publications 2013 Proceedings of the Institution of Mechanical Engin Vol.227 No.11

<P>In this study, a new controllable engine mounting system for vibration control of passenger vehicles is proposed. The proposed mounting system consists of two smart material actuators: a piezostack actuator and a magnetorheological-fluid actuator. First, the dynamic responses of an in-line four-cylinder engine supported by three rubber mounts are mathematically analysed by considering the six-degree-of-freedom motion of the engine body, whose excitation is generated by the inner forces during the engine combustion process. Second, the proper positions of the two actuators are determined. Two magnetorheological mounts are used as roll mounts, and one piezostack mount is used as the right-hand mount, in order to reduce the unwanted engine vibration in a broadband frequency range. Third, the piezostack mount and the magnetorheological mount are designed and manufactured, followed by installation in the engine mounting system. Subsequently, for effective vibration isolation, a sliding-mode controller, which is robust to disturbances and system uncertainties, is designed. Finally, in order to demonstrate the effectiveness of the proposed new engine mounting system, vibration control performances are evaluated by adopting the hardware-in-the-loop simulation test method associated with the sliding-mode controller. The vibration control responses are presented at various engine operating speeds in the time domain and the frequency domain. It was found that the vibration control performance is improved by 30% at an engine speed of 750 r/min and by 17% at an engine speed of 2000 r/min using the proposed engine mounting system associated with the controllers.</P>

Design and Numerical Study of Hybrid Magnetic Source Disc-type Magnetorheological Valve

Xiaolong Yang,Yan Li,Youming Zhou,Shiying Zhou,Jiehong Zhu 한국자기학회 2023 Journal of Magnetics Vol.28 No.2

Magnetorheological valves are important components in hydraulic systems that provide precise position control. At present, the low-pressure drop performance of magnetorheological valves is the main problem limiting their application. To improve the pressure drop performance of magnetorheological valves, a hybrid magnetic source disc magnetorheological valve is proposed. The magnetic pressure drop model and viscous pressure drop model of the hybrid magnet source disc type magnetorheological valve based on the Bingham model are Derived. Magnetic field distributions in the damping channel of the hybrid magnet source disc type magnetorheological valve are obtained by using ANSYS finite element analysis software. The mathematical model of the relationship between pressure drop and magnetic induction intensity was established using Matlab software, and the effects of parameters such as effective current, axial damping gap, radial damping gap, and coil width on the pressure drop performance of disc-type magnetorheological valves with hybrid magnetic sources were numerically analyzed. The results show that the pressure drop of the disc magnetorheological valve with a hybrid magnetic source can reach 10.9935 MPa at the current I=3A, axial damping gap ga=1 mm, and radial damping gap gr=1.5 mm. Compared with the conventional disc magnetorheological valve, the pressure drop performance of the hybrid magnetic source disc magnetorheological valve is improved by 28 %, which provides ideas on how to improve the pressure drop performance of the magnetorheological valve.

Optimal design of magnetorheological fluid-based dampers for front-loaded washing machines

Nguyen, QH,Choi, SB,Woo, JK Professional Engineering Publishing Ltd 2014 Proceedings of the Institution of Mechanical Engin Vol. No.

<P>In this research, a magnetorheological fluid-based damper to attenuate vibration due to unbalanced laundry mass from a front-loaded washing machine is proposed and optimally designed with experimental validation. First, rigid vibration mode of the washing machine due to an unbalanced mass is analyzed, and an optimal positioning of the suppression system for the washing machine is figured out. In order to attenuate vibration from the washing machine, several configurations of magnetorheological damper are proposed considering available space and the required damping force of the system. Based on the Bingham rheological model of magnetorheological fluid, damping force of the proposed magnetorheological dampers is then derived. An optimal design problem for the proposed magnetorheological damper is constructed considering its zero-field friction force and the maximum damping force. The optimization objective is to minimize the zero-field friction force of the magnetorheological damper while the maximum value of damping force is kept being greater than a required value. An optimization procedure based on finite element analysis integrated with an optimization tool is employed to obtain optimal geometric dimensions of the magnetorheological dampers featuring different types of magnetorheological fluid. Optimal solutions of the magnetorheological dampers are then presented and the optimized damper is figured out. In addition, performance characteristics of the optimized magnetorheological damper are presented and discussed.</P>

Effect on the Sedimentation Stability of Magnetorheological Fluid by Micro-nano Composite System

Ji Jinjie,Wu Xiangfan,Tian Zuzhi 한국자기학회 2023 Journal of Magnetics Vol.28 No.2

In magnetorheological devices, the magnetorheological fluids are inevitably in a zero-field state when the MR device is out of work. Long-term placement will lead to the sedimentation of MR fluids, reducing the performance of the magnetorheological device. A novel magnetorheological fluid was prepared by mixing microparticles and nanoparticles to solve this problem. After one-week placement, the sedimentation rate of the novel magnetorheological fluid is only 0.23 %, decreased by 88.5 % compared with general magnetorheological fluid. The novel magnetorheological fluid shows excellent sedimentation stability, keeping magnetorheological devices in good condition.

Research on Temperature Field of a New Type of Magnetorheological Fluid Dynamometer with Cooling System

Lei Wang,YiPing Luo,Hui Ying Liang,Meng Ji 한국자기학회 2019 Journal of Magnetics Vol.24 No.4

In order to study the temperature characteristics of magnetorheological fluid dynamometer, the torque model and working principle of magnetorheological fluid dynamometer were analyzed, the temperature experiment of magnetorheological fluid dynamometer was conducted, and the experimental data were analyzed and processed in this paper. The fitting curves between the speed of magnetorheological fluid dynamometer and the experimental temperature, the speed and the torque, the current and the torque as well as the current and the temperature were obtained. Then, the temperature field of magnetorheological fluid was simulated by FLUENT based on the experimental data. The temperature field nephograms and temperature values of test points under different working conditions were obtained. Comparing the experimental values with the simulation values, the relative error was less than 7.8 %, which was within a reasonable range. Finally, from the aspect of temperature reduction, the simulation model was optimized. Based on the principle of heat convection, the simulation model was reconstructed. The maximum temperature drop was 10℃.

Design optimization of magnetorheological damper geometry using response surface method for achieving maximum yield stress

A. J. D. Nanthakumar,J. JANCIRANI 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.9

Field controllable magnetorheological (MR) damper has gained prominence as a suitable vibration control device for a wide variety of applications as they offer the combined advantages of high-performance metrics of a fully active vibration control system with the cost metrics of a passive vibration control system. The functional quantity that influences the damping performance of a magnetorheological damper is the yield stress of the magnetorheological fluid across the fluid flow gap when the magnetic field is applied. To achieve maximum damping output from the magnetorheological damper, the geometry of the damper piston needs to be optimized. The main geometrical design parameters of the damper piston are the pole width, magnetorheological fluid flow gap, distance between piston rod and coil and the outer pole thickness. The optimization of the damper geometry is carried over with magnetic field strength and yield stress as response variables in two different iterations. A quadratic polynomial function is considered for both the response variables. The yield stress response variable is found to exhibit a more accurate following through the regression equation and it is selected as the response variable of choice. The individual effect of each of the design variable and the interaction effect of the design variables over the yield stress response variable is studied in this research paper. The optimal values of the piston geometry could be used to fabricate a magnetorheological damper prototype in future study.

Design and performance analysis of magnetorheological grease flexible manipulator gripper

Xudan Ye,Jiqiang Dong,Wenchao Wang,Jing Lu,Jiong Wang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.3

To address the issue of traditional manipulators being unable to grasp and operate objects of varying shapes or easily damaged objects in some work scenes, a new type of flexible manipulator with magnetorheological grease based on the magnetorheological effect was developed. Comsol was used to simulate the magnetic field of the flexible gripper. The results showed that as coil current increased, the magnetic induction intensity increased, the magnetic induction line began to close to the rubber capsule after the shell support was added, the magnetorheological grease solidified after the magnetic field was applied, and the object could be wrapped and grasped. Then the kinematics and grasping ability of the flexible manipulator with magnetorheological grease in the grasping process are analyzed. Finally, an experimental test platform for the magnetorheological grease flexible manipulator is built, and under different currents (0 A, 0.25 A, 0.5 A, 0.75 A, 1 A), the flexible manipulator is tested for different gripping depths (6 mm, 11 mm, 17.5 mm) and a variety of diameter wooden balls (15 mm, 40 mm, 60 mm) gripping ability. The results show that when the gripping depth is constant, the envelope angle of the flexible fingertip to the sphere decrease with the increase of the diameter of the sphere, and when the diameter of the sphere is constant, the higher the grasping depth of the flexible fingertip, the larger the envelope angle to the sphere.

Design and Performance Study of Hybrid Channel-valved Magnetorheological Dampers

Yan Li,Xiaolong Yang,Jiehong Zhu,Youming Zhou 한국자기학회 2023 Journal of Magnetics Vol.28 No.1

In order to solve the problem of low damping force caused by low utilization of magnetic field in traditional magnetorheological dampers, a hybrid channel valve type magnetorheological damper with circular channel and disk channel are proposed. The main content of this paper is to design the basic structure of mixed channel valve magnetorheological damper. The mathematical model of damping force based on Bingham plastic model was established from the design of magnetic circuits. The two-dimensional simulation model of MR Damper was established by using EMAG module in ANSYS finite element analysis software, and the magnetic circuit of mixed channel valve MR Damper was simulated and analyzed. The results show that the output damping force of the hybrid channel valve-type magnetorheological damper is 18 KN and the adjustable coefficient is 14.52 with the current I of 3A, the number of coil turns of 560, the axial damping gap of 1 mm and the radial damping gap of 1.5 mm.

Mechanical and psychophysical performance evaluation of a haptic actuator based on magnetorheological fluids

Ryu, Semin,Koo, Jeong-Hoi,Yang, Tae-Heon,Pyo, Dongbum,Kyung, Ki-Uk,Kwon, Dong-Soo SAGE Publications 2016 Journal of intelligent material systems and struct Vol.27 No.14

<P>This study presents a miniature haptic actuator (10mm (L)x10mm (W)x6.5mm (H)) based on magnetorheological fluids, which is designed to provide realistic touch sensations to users. Its primary goals are to evaluate mechanical or actuation performances of the prototype magnetorheological actuator and to assess its effectiveness in conveying haptic sensations to users by conducting the psychophysical experiments. The mechanical performance study evaluated the prototype's output forces from haptic perspectives using a dynamic test frame. The psychophysical experiments studied human subjects' perceptions on haptic sensations produced by the prototype. The mechanical test results show that the magnetorheological actuator is capable of generating a wide range of frequency-dependent output forces (from 1.5N to nearly 9N). The psychophysical experiments show that the actuator offers various kinesthetic and vibrotactile sensations to human operators. Overall, the results suggest a feasibility of using the magnetorheological haptic actuator in real-world applications, such as a haptic keypad and functional buttons in small consumer electronics and hand-held devices.</P>

Influence of Temperature on Torque Transmission Stability of Magnetorheological Fluid

Zuzhi Tian,Xiangfan Wu,Xingming Xiao,Li Hao Korean Magnetics Society 2018 Journal of Magnetics Vol.23 No.4

Aiming to obtain the influence mechanism of temperature on the torque transmission stability of magnetorheological fluid, firstly, a magnetorheological transmission device and its test-bed are established, and then, the thermal expansion, temperature pressure effect, heat volatilization, viscosity temperature characteristic, magnetic temperature characteristic and other related temperature characteristics were experimented systematically. The results indicate that the thermal expansion rate of 30 wt% magnetorheological fluid is 6 % and 18 % respectively at 120°C and 220°C, and the working space pressure is 13 kPa when the temperature rises from 32°C to 63°C. The thermal volatilization rate is still lower than 1 % at 200°C for 8 hours. The viscosity of the silicone oil based magnetorheological fluid decreases by 78 % when the temperature increases from 20°C to 240°C, and the saturation magnetization decreased by 6.2 %, 13 % and 23 % respectively at 150°C, 250°C and 350°C. Furthermore, the temperature field distribution experiment shows that the highest temperature region is at the outer diameter of the disk and expands slowly along the radial direction. Moreover, compared with rotational speed, temperature is the main factor affecting the torque fluctuation of magnetorheological fluid.