Experimental Investigation on Boring Tool Vibration Control Using MR Fluid Damper

2016 ◽  
Vol 15 (01) ◽  
pp. 13-25 ◽  
Author(s):  
E. Mohan ◽  
U. Natarajan

In the manufacturing industry, most of the components are made by machining operations. The performance of the product to a large extent is dependent on the accuracy and consistency of the machining processes. Various parameters are considered to achieve the high quality of the machining. Out of which, vibration is one of the important parameters that will lead poor quality of the product and also reduce the tool life. Vibrations are induced by metal cutting operation during machining. Turning operations and especially boring operations are associated with severe vibration-related problems. Boring operation is often done with a boring bar, which is necessarily long and slender so that it can fit into the multipart work piece geometry. Such tools are lack of dynamic stiffness and stability, this manufacturing operation is repeatedly plagued with self-excited vibrations known as chatter. Magnetorheological (MR) fluid is employed in this research work to control the vibration of a boring tool. The MR fluid damper has received great attention due to its ability to reversibly change from a free flowing, linear, viscous liquid to a semi-solid when exposed to magnetic fields in just a few milliseconds and was also found to be effective in suppressing tool vibration. Vibration control during machining process is an important tactic to suppress the chatter vibration. The aim of this approach is to reduce the relative displacements between the tool and the work piece during the machining process.

Author(s):  
Jianxiao Wang ◽  
Guang Meng ◽  
Eric Hahn

A squeeze mode MR fluid damper used for rotor vibration control is designed and manufactured, and the unbalance response properties and control method of a single-disk flexible rotor system supported by the damper are studied experimentally. It is found from the study that the magnetic pull force can decrease both the first critical speed and the critical amplitude; the oil film reaction force can decrease the amplitude at the undamped critical speeds, but increase the amplitude in a speed range between two undamped critical speeds. For the rotor system supported by a journal bearing and an MR fluid damper, it is possible to appear oil film instability as the increasing of the control current. The damper may have the best effect to make the vibration minimize within the range of all working speed by using on-off control method. The research show that the squeeze mode MR fluid damper has the advantages such as simple structure, clearly effectiveness, quick response, etc., and this kind of damper has a promising potential future in vibration control of flexible rotor systems.


Author(s):  
T. S. Aravindhan ◽  
K. Gupta

Application of two smart materials, namely shape memory alloy (SMA) and magnetorheological fluid (MRF) for rotor vibration control is explored to control the synchronous vibration of rotors crossing resonance condition. First a single degree of freedom system is analyzed to study the effect of SMA and MR fluid damper individually, and then the simulations are repeated to find the feasibility of using the two smart materials simultaneously. An MRF damper is designed, fabricated and installed on a rotor system. The fabricated MR damper is tested and an ANFIS model is trained to predict the damper force in the simulations carried out. The experimental rotor model is analyzed using finite element method in Matlab™. Simulations are carried out to study the effect of MR damper on rotor vibration response. Experimental results obtained from the rotor model with the fabricated MRF damper show considerable reduction in peak vertical amplitude as the current in the MR damper coils is increased. A good correlation between the theoretical and experimental results is observed.


2005 ◽  
Vol 11 (2) ◽  
pp. 263-276 ◽  
Author(s):  
J. Wang ◽  
G. Meng

A shear mode magnetorheological (MR) fluid damper used for rotor vibration control is designed and manufactured, and the theoretical model of a cantilevered rotor system with the MR fluid damper is established. The response properties of the rotor system are studied theoretically and experimentally. It is found from the study that the Coulomb friction of the damper is increased as the magnetic field strength applied to the MR fluid increases. As a result, the vibration amplitude of the rotor system supported by the MR damper is decreased near the undamped critical speeds, but is increased in a rotating speed range between the first and the second undamped critical speeds. At the same time, the damped critical speed of the rotor system is increased with the increase of the applied magnetic field. Based on these characteristics, a simple on-off control method is used to suppress the rotor vibration across the critical speeds, and the results show that the method is very effective.


2002 ◽  
Vol 8 (4) ◽  
pp. 527-547 ◽  
Author(s):  
C. Y. Lai ◽  
W. H. Liao

Semi-active control systems are becoming more popular because they offer both the reliability of passive systems and the versatility of active control without imposing heavy power demands. It has been found that magneto-rheological (MR) fluids can be designed to be very effective vibration control actuators. The MR fluid damper is a semi-active control device that uses MR fluids to produce a controllable damping force. The objective of this paper is to study a single-degree-of-freedom suspension system with an MR fluid damper for the purpose of vibration control. A mathematical model for the MR fluid damper is adopted. The model is compared with experimental results for a prototype damper through finding suitable model parameters. In this study, a sliding mode controller is developed by considering loading uncertainty to result in a robust control system. Two kinds of excitations are inputted in order to investigate the performance of the suspension system. The vibration responses are evaluated in both time and frequency domains. Compared to the passive system, the acceleration of the sprung mass is significantly reduced for the system with a controlled MR damper. Under random excitation, the ability of the MR fluid damper to reduce both peak response and root-mean-square response is also shown.


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