PERFORMANCE EVALUATION OF FREIGHT VEHICLES USING MULTIBODY MODELLING APPROACH

Abstract

Although railway vehicles were first used in the 19th century, it was only in the 20th century that engineers began to understand their dynamics and were able to write down, and solve, their equations of motion. The single most fundamental property of a railway vehicle is the use of a steel wheel running on a steel rail with all the traction, braking and guidance forces being transmitted through a small contact area between the wheel and the rail. It is well known that a mechanical system that is subject to non-conservative forces may become dynamically unstable under certain conditions. In a railway vehicle the non-conservative forces arise at the contact point between the wheel and rail due to creepage, and the sustained lateral and yawing oscillation that results in some vehicles, known as hunting motion. The transportation of goods has assumed much larger importance in view of growing economy in India. Indian railways is planning and. developing dedicated freight corridors between major metropolitan cities. It. is also proposed to increase the axle load from the present load of 22 tonnes to 30 tonnes. In view of these developments design of freight bogies has become critical since this will affect the Indian railways transportation capacity to a large extent_ This present report deals with the modelling of freight railway vehicles with two types of freight bogie (a) Three piece bogie and (b) Y25 bogie, in which we define all the inertia parameters of parts of bogie and carbody and also suspension parameters like stiffness and. damping. For these rail vehicles we are using Multibody modelling software GENSYS, and finally after modelling the vehicle, we simulate the vehicle on railway track model and evaluate their performance parameters and compare their performances.