A STUDY OF SUSPENSION SYSTEM OF HIGH SPEED TRAINS

Abstract

The current thesis deals with a theoretical study of the various railway suspension systems available and exhibit their effect on passenger ride comfort for high speed trains. Initially, the performance of a rail vehicle with passive damping system is investigated with the help of a Multi Body Dynamic simulation software VI-RAIL using parameters specified by Indian railways. Then, the performance of a semi-active damper based rail vehicle is exhibited with the help of nine degree of freedom rail vehicle model developed in MATLAB’s SIMULINK. The improvement in the ride quality of the rail vehicle is shown by utilising magneto rheological (MR) damper as a part of its secondary suspension system. The MR damper system is modelled with the help of Bouc-Wen model. Linear Quadratic Gaussian (LQG) law of control is utilised to evaluate the optimum damping forces which are fed into the MR dampers after being converted into voltage signals. The acceleration responses of the vehicle in the passive state (with MR damper inactive) are compared to the vehicle equipped with MR damper in both time as well as frequency domain. The RMS values of acceleration and Sperling’s ride quality index indicated significant improvement in ride quality for the vehicle with MR damping system over passive damped system.