An experimental analysis of magnetorheological (MR) damping for vibration mitigation

WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
William Ralph Deaton IV (Creator)
Western Carolina University (WCU )
Web Site:
Sudhir Kaul

Abstract: Magnetorheological (MR) dampers have emerged as a viable means of semi-active damping in multipleindustry applications. The semi-active nature of these dampers is a significant attribute since the damperfunctions as a passive damper in the event of a failure. While there have been other smart materials likeferroelectric, piezoelectric, shape memory alloys, etc. that have been successfully used, MR fluids exhibita unique combination of completely reversible effect, very low response time, high durability and verylow energy requirements that make them suitable for vibration control in a wide variety of applications.This study presents results from an experimental investigation that has been carried out to evaluate theperformance of a MR damper for vibration mitigation. The capability of a commercial MR damper toisolate a payload from base excitation is analyzed and the damper parameters are identified to simulatethe capability of the damper with regards to transmissibility. Simulation results are presented for multiplelevels of damping exhibited by the MR damper. Multiple iterations of testing have been performed inorder to evaluate the influence of variables such as input current to the electromagnet of the damper, massof the payload, excitation frequency and excitation amplitude. Although temperature is known to be asignificant parameter that influences the performance of the MR damper, it has not been critical for thepurposes of this study. This can be primarily attributed to the small displacement amplitudes that havebeen used for excitation. Results indicate that the MR damper is successful in mitigating vibrationstransmitted to the payload. Vibration mitigation is quantified by comparing the root mean square (RMS)of the time history of acceleration of the base with that of the payload. Peak values of acceleration are also compared. Displacement transmissibility results directly demonstrate the variable damping capabilityof the MR damper. Although the stiffness constant of the damper may also change, it is not seen to varyappreciably in this study since the excitation amplitude is limited to a low threshold. The damper is foundto be robust with an inherent ability of handling payload and excitation variability. It is observed thatincreasing the input current to the electromagnet around the MR fluid directly results in an increase indamping, therefore, making the use of these dampers viable in applications where payloads and excitationinputs are expected to change during operation. These features of robustness and controllability make theuse of MR dampers very attractive in a large range of applications.

Additional Information

Language: English
Date: 2015
Damping, Magnetorheological, Magneto-rheological, Vibration
Magnetorheological fluids
Damping (Mechanics)
Vibration -- Measurement

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