Abstract
Investigation of vibration is an important topic for the purposes of ride comfort in railway engineering. The vibration of rail vehicles becomes very complex because it is affected by the condition of vehicles, including suspensions and wheel profile, condition of track sections, including rail profile, rail irregularities, cant and curvature. The present study deals with the effects of railway track imperfections on dynamic behavior, and investigates the effect of vehicle speed and the rail irregularity on ride comfort through numerical simulation. The numerical simulation of the vertical dynamic behavior of a typical railroad vehicle will be performed using Largrangian dynamics. The model consists of 17 degrees of freedom with 4 wheel-sets, 2 bogies and a car body. For the assessment of the ride comfort, the Sperling ride index (ISO2631) is calculated using filtered RMS accelerations. The ride characteristics of the vehicle provide an assessment of the dynamic behavior of the vehicle through the analysis of the accelerations at the vehicle body, whereas the ride comfort assesses the influence of the vehicle dynamic behavior on the human body. A parametric study was carried out to suggest design modifications in order to improve the level Sperling index.