Research on the Boring Chatter Suppression Based on MR Fluid

2006 ◽  
Vol 532-533 ◽  
pp. 365-368
Author(s):  
Tian Rong Kong ◽  
Zhe He Yao ◽  
Zi Chen Chen
Keyword(s):  
Magnetic Field ◽  
Experimental System ◽  
Machining Accuracy ◽  
Mr Fluid ◽  
Boring Bar ◽  
Chatter Suppression ◽  
Excitation Coil ◽  
Precision Hole ◽  
Stiffness And Damping ◽  
Working Efficiency

Chatter during boring process is one of the main adverse factors influenced on the machining accuracy of precision hole, surface quality and working efficiency. In order to suppress chatter, an innovative controlling means of MR-intelligent-boring-bar with self-chatter-suppression is proposed, which is composed of MR fluid, shell structure, excitation coil and boring bar. The MR fluid’s mechanical characteristic can be adjusted by changing the intensity of magnetic field, thus the system stiffness and damping will be modified, and then the boring chatter can be suppressed. Otherwise, the dynamic model of MR-intelligent-boring-bar with self-chatter-suppression is built. Lastly, the experimental system of MR-intelligent-boring-bar is established, and the experiments of chatter suppression during boring process are performed. The results of experiments show that the new means of chatter suppression is effective.

Development of a boring bar with magneto rheological fluid damping and assessment of its dynamic characteristics

2017 ◽  
Vol 24 (14) ◽  
pp. 3094-3106 ◽  
Author(s):  
CV Biju ◽  
MS Shunmugam
Keyword(s):  
Modal Parameters ◽  
Model Parameters ◽  
Excitation Current ◽  
Mr Fluid ◽  
Boring Bar ◽  
Chatter Suppression ◽  
Damping Characteristics ◽  
Fluid Damping ◽  
Variable Damping ◽  
Magneto Rheological

The boring operation is prone to chatter as the boring bar is slender and has an overhang. For chatter suppression, passive, semi-active or active control methods can be employed. In the present work, a boring bar has been specially designed to transfer vibration to a cantilever bar surrounded by magneto rheological (MR) fluid. The MR fluid when exposed to electromagnetic flux changes its rheological property within a certain range. Thus, the boring bar is able to exhibit variable damping characteristics by changing the excitation current. The modal parameters are experimentally obtained through an impact test and a shaker test. The variation of modal parameters with excitation current is discussed. A stability lobe diagram is also developed from the model parameters, showing safe and unsafe regions for operation. The semi-active boring bar developed in the present work can be used for the suppression of chatter during the boring operation.

Chatter Suppression with Magnetic Damping in Turning of Stainless Steel AISI 304

2013 ◽  
Vol 393 ◽  
pp. 183-188 ◽  
Author(s):  
Ummu Atiqah Khairiyah B. Mohammad ◽  
A.K.M.N. Amin ◽  
Muhd Amir Hafiz Bin Ahamad Mahrodi ◽  
Muammer D. Arif
Keyword(s):  
Magnetic Field ◽  
Stainless Steel ◽  
Permanent Magnet ◽  
Surface Finish ◽  
Machining Accuracy ◽  
Aisi 304 ◽  
Tool Holder ◽  
Chatter Suppression ◽  
Steel Aisi ◽  
Stainless Steel Aisi

Chatter is almost an unavoidable phenomenon during machining, normally accompanied by a characteristic sharp and monotonous noise. Apart from noise pollution in the industry, chatter leaves a bad surface finish on the part and negatively influences dimensional tolerances, reduced productivity, excessive tool wear and damaged machine-tool components. Therefore, chatter avoidance is utmost importance. However, a deeper investigation into chatter formation reveals that chatter appears during metal cutting process as a result of resonance caused by interaction of the prominent natural frequencies of the system with the frequency of chip serration. This paper presents an innovative approach to chatter suppression during turning of stainless steel AISI 304 applying permanent magnet from the bottom of the tool holder to increase the damping coefficient of the tool holder, since it has been identified that the tool holder is the main vibrating component during turning. A special fixture was designed, fabricated and mounted on the carriage of a conventional turning machine Harrison M390 for holding a permanent magnet bar. The variable cutting parameters were - cutting speed, feed rate and depth of cut at constant tool overhang of 120 mm. The experiments were designed based small Central Composite Design (small CCD) based on the Response Surface Methodology (RSM) approach using DESIGN EXPERT (DOE) software. The experiments were performed under two different conditions, the first under normal conditions, while the other was under the application of magnetic field from permanent magnet located side direction of the tool holder. The experiments focused on monitoring the vibration signals using a vibration data acquisition system during turning operation. Analysis of the recorded signals in the FFT domain indicated significant reduction of chatter when a magnetic field is applied. It is apparent that a reduction of chatter amplitude will result in improved surface finish, tool life, machining accuracy, productivity, as well as reduction of operation.

scholarly journals Tunable Stiffness and Damping Study on Flexible PVC Cantilever Structure Embedded with MR Fluid

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5024
Author(s):  
Gunasekaran Ramkumar ◽  
Arul Jesu Gnanaprakasam ◽  
Marimuthu Thirumarimurugan
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Cross Section ◽  
Rectangular Cross Section ◽  
Magnetic Flux Density ◽  
Mr Fluid ◽  
Cantilever Structure ◽  
Host Structure ◽  
Stiffness And Damping ◽  
Tunable Stiffness

The stiffness and damping of a flexible smart cantilever structure controlled by a magnetic field is investigated in this research. The cantilever structure is fabricated by using flexible polyvinyl chloride as a host structure of rectangular cross-section embedded with magnetorheological (MR) fluid. The deflection of the cantilever structure at the free end is used to analyze the stiffness change of the cantilever structure. The stiffness of the specimen with MR fluid at magnetic flux density of 0.171T is greater than that of the specimen without subjected to magnetic field. The strength of the applied magnetic field is directly related to the structure’s stiffness. Under the influence of a magnetic field, the MR fluid embedded inside the flexible PVC cantilever structure significantly dampens the vibrations of the structure.

Investigation of ultrasonic properties of MR fluid under various sweep rates of magnetic field

2013 ◽  
Vol 49 (3-4) ◽  
pp. 430-433
Author(s):  
A. Isnikurniawan ◽  
Y. Fujita ◽  
S. Tanimoto ◽  
T. Sawada
Keyword(s):  
Magnetic Field ◽  
Mr Fluid ◽  
Ultrasonic Properties

Dynamic characteristics of squeeze-type mount using magnetorheological fluid

2005 ◽  
Vol 219 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Y K Ahn ◽  
J-Y Ha ◽  
Y-H Kim ◽  
B-S Yang ◽  
M Ahmadian ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Vibration Isolation ◽  
Dynamic Behaviour ◽  
Electrical Current ◽  
Magnetorheological Fluid ◽  
Test Set ◽  
Mr Fluid ◽  
Set Up ◽  
Stiffness And Damping

This paper presents an analytical and experimental analysis of the characteristics of a squeeze-type magnetorheological (MR) mount which can be used for various vibration isolation areas. The concept of the squeeze-type mount and details of the design of a squeeze-type MR mount are discussed. These are followed by a detailed description of the test set-up for evaluating the dynamic behaviour of the mount. A series of tests was conducted on the prototype mount built for this study, in order to characterize the changes occurring as a result of changing electrical current to the mount. The results of this study show that increasing electrical current to the mount, which increases the yield stress of the MR fluid, will result in an increase in both stiffness and damping of the mount. The results also show that the mount hysteresis increases with increase in current to the MR fluid, causing changes in stiffness and damping at different input frequencies.

scholarly journals Study on the Unbalanced Curl Seal Failure of the Magnetorheological Fluid Sealing Device of the Hydraulic Turbine Main Shaft under Different Speed Abrupt Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1171
Author(s):  
Jie Cheng ◽  
Zheng-Gui Li ◽  
Yang Xu ◽  
Wang-Xu Li ◽  
Xin-Rui Li
Keyword(s):  
Magnetic Field ◽  
Sudden Change ◽  
Hydraulic Turbine ◽  
Frictional Heat ◽  
Main Shaft ◽  
Mr Fluid ◽  
Friction Heat ◽  
Sealing Ability ◽  
Sealing Failure ◽  
Sealing Device

The fluid flow in the runner of a hydraulic turbine has serious uncertainties. The sealing failure of the magnetorheological (MR) fluid sealing device of the main shaft of the hydroturbine, caused by a sudden change in speed, has always been a difficult topic to research. This study first derives the MR fluid seal pressure and unbalanced curl equations of the hydroturbine main shaft, and then analyzes the seal pressure and friction heat under different rotational speed mutation conditions through experiments. After verification, the temperature field and magnetic field distribution of the MR fluid sealing device of the main shaft of the hydraulic turbine are obtained via numerical calculation. The results show that the external magnetic field affects the magnetic moment of the magnetic particles in the MR fluid, resulting in a significant change in frictional heat, thereby reducing the saturation of magnetic induction intensity of the MR fluid. This results in a decrease in the sealing ability of the device. The size and abrupt amplitude of the main shaft of the hydraulic turbine, and friction heat is positively correlated reducing the sealing ability of the device and causing sealing failure. Based on our results, we recommend adding the necessary cooling to the device to reduce the frictional heat, thereby increasing the seal life of the device.

Internal Organizational Measurement for Control of Magnetorheological Fluid Properties

2006 ◽  
Vol 129 (4) ◽  
pp. 423-428 ◽  
Author(s):  
John R. Lloyd ◽  
Miquel O. Hayesmichel ◽  
Clark J. Radcliffe
Keyword(s):  
Magnetic Field ◽  
Physical Properties ◽  
High Sensitivity ◽  
Time Varying ◽  
Measurable Effect ◽  
Mr Fluid ◽  
Fluid State ◽  
Mr Fluids ◽  
Fluid Properties ◽  
Field Excitation

Magnetorheological (MR) fluids change their physical properties when subjected to a magnetic field. As this change occurs, the specific values of the physical properties are a function of the fluid’s time-varying organization state. This results in a nonlinear, hysteretic, time-varying fluid property response to direct magnetic field excitation. Permeability, resistivity and permittivity changes of MR fluid were investigated and their suitability to indicate the organizational state of the fluid, and thus other transport properties, was determined. High sensitivity of permittivity and resistivity to particle organization and applied field was studied experimentally. The measurable effect of these material properties can be used to implement an MR fluid state sensor.

Wear Behavior of Rotary Lip Seal Operating in a Magnetorheological Fluid Under Magnetic Field Conditions

2017 ◽  
Vol 140 (2) ◽  
Author(s):  
Peng Zhang ◽  
Kwang-Hee Lee ◽  
Chul-Hee Lee
Keyword(s):  
Magnetic Field ◽  
Smart Materials ◽  
Wear Behavior ◽  
High Volume ◽  
Magnetorheological Fluid ◽  
Engine Oil ◽  
Wear Properties ◽  
Lip Seal ◽  
Sealing Performance ◽  
Stiffness And Damping

A magnetorheological fluid (MRF) is one of many smart materials that can be changed their rheological properties. The stiffness and damping characteristics of MRF can be changed when a magnetic field is applied. This technology has been successfully employed in various low and high volume applications, such as dampers, clutches, and active bearings, which are already in the market or are approaching production. As a result, the sealing performance of MRF has become increasingly important. In this study, the wear properties of seals with MRFs were evaluated by a rotary-type lip seal wear tester. The test was performed with and without a magnetic field. The leakage time was monitored during the tests in typical engine oil conditions. The results showed that the wear resistance of the seal with MRF was decreased under the magnetic field.

scholarly journals Investigation on the Mechanical Properties of MRE Compounds

Machines ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 36 ◽  
Author(s):  
Renato Brancati ◽  
Giandomenico Di Massa ◽  
Stefano Pagano
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Testing Machine ◽  
Static Test ◽  
Vibration Isolators ◽  
Elastomeric Matrix ◽  
Magneto Rheological ◽  
Stiffness And Damping ◽  
Rheological Effect

This paper describes an experimental investigation conducted on magneto-rheological elastomers (MREs) with the aim of adopting these materials to make mounts to be used as vibration isolators. These materials, consisting of an elastomeric matrix containing ferromagnetic particles, are considered to be smart materials, as it is possible to control their mechanical properties by means of an applied magnetic field. In the first part of the paper, the criteria adopted to define the characteristics of the material and the experimental procedures for making samples are described. The samples are subjected to a compressive static test and are then, adopting a testing machine specially configured, tested for shear periodic loads, each characterized by a different constant compressive preload. The testing machine is equipped with a coil, with which it is possible to vary the intensity of the magnetic field crossing the sample during testing to evaluate the magneto-rheological effect on the materials’ characteristics in terms of stiffness and damping.

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