DYNAMIC ANALYSIS OF SIMPLE VEHICLES ON RANDOM TRACK BY DIGITAL SIMULATION

Abstract

A linearised model of a railway wagon as vehicle is considered. i -T.he►~rvehic.Ie;. with heave and pitch degrees of freedom moves over a random uneven surface with constant velocity. The input base excitation to the vehicle is digitally simulated for a given power spectrum. Various configurations of vehicle cargo-mass system are considered. It is found that greater eccentricity of the cargo is responsible for large response. This is specially true for pitch displacement. The system behaviour is of first order characterstics for small velocities and is of second order for large velocities. Response variation for different base length and stiffness has been also studied. It is found that small base length provides large pitch displacement response and heave response does not vary significantly. For small stiffness, the heave response reduces but pitch displacement response increases with the reduction in spring stiffness. Several cases have been considered to assess the response characterstics statistically.