Parametric Study of Suspension Elements for Ride Index Analysis of an Indian Railway Freight Vehicle

Approximately three hundred thousand three-piece bogie freight vehicles presently operate under Indian Railways. The dynamic behavior of a vehicle depends on primary and secondary suspension elements. In the present work, a parametric study of suspension elements has been performed at various operating speeds to analyze the ride index of vehicle. The freight vehicle model considered in the present work comprises 70 degrees of freedom (DOF). Spring indices of various springs used as suspension elements and damping coefficients of wedge block as well as elastomeric pad have been obtained experimentally. These values have been used along with actual recorded track irregularities data to solve a vehicle model using ADAMS/Rail. The behavior of vertical acceleration and ride index of the vehicle for different speeds limits have been observed. The parameters of suspensions elements have been sequentially varied and their effects on vertical acceleration and ride index have been studied for vehicle speeds up to 110 kmph. A new set of parameters for suspension elements which gives improved ride index has been suggested on the basis of results obtained.