Experimental investigations of damping characteristic for MR strut by half-power bandwidth method

Abstract

In today's automobile, each and every part of vehicle must consider the vibration management. Damping and isolation are the two aspects of vibration management which uses in conjunction to attain the required performance. The Logarithmic decrement method and Bandwidth method are the two major methods for measurement of damping in vibration system. Time domain method is used in Logarithmic decrement whereas the Half power bandwidth method is used in frequency domain analysis. In the present work, quarter car model is used to determine the frequency response analysis of Magnetorheological damper strut. The sprung mass is varying from 82 kg to 132 kg and excitation force is given by cam mechanism which is designed as per the bump size specified by Indian Road Congress (IRC) standard. The fabricated MR damper is tested at different sprung mass with input current from 0.1 A to 0.5 A. It is observed that the damping ratio is varying from 0.04 to 0.21. The results obtained in this paper will be helpful for the Indian auto industry to make more economical and reliable damper strut.

Comparison of Dynamic Performance of an All-Metallic Vibration Isolator by Elliptic Method and Frequency Sweeping Method

“…When the frequency sweeping method is used for the dynamic test, the loss factor can be calculated for isolators with small damping (approximately symmetrical relative to the resonant point), which can be expressed as [25]:…”