Simulation of Railway Vehicle Dynamics in Universal Mechanism Software

Abstract This abstract describes the experience of a railway vehicle dynamics simulation using Universal Mechanism software. The software system Universal Mechanism (UM) was created for computer simulation of kinematic and dynamic processes of different mechanical systems, it is especially efficient for railway rolling stock simulations tasks. UM software includes different models (simplified and 3D models) of railway rolling stock and different software tools for simulation of railway vehicle dynamics. Researchers at the VGTU Railway Transport Department constantly and successfully use the UM for the educational and research purposes. For example the UM software was used for the simulation of a railway accident on the track between stations Gaižiūnai and Skaruliai. In this case six wagons derailed in very complicated circumstances. To determine the actual cause of the accident, the computer two stage model of the accident was created: at the first stage the simplified model was created and at the second stage the 3D simulation of the train dynamics was made. After creating the dynamic model of the train and analyzing the results, it was determined that the UM simulates only a single braking process of the train. That does not reliably recreate the conditions of the train and the train longitudinal conditions in the simulation process are absolutely unpredictable. That distorts the results of the simulation. Working in collaboration with the manufacturer of the UM − Laboratory of Computational Mechanics of Bryansk State Technical University, the UM software has been supplemented with the new feature which creates multibraking conditions of the train. The new version of the UM was made to re-model various train braking processes (service braking, releasing and emergency braking) with full restoration of black box tape recordings. This suggests that the results of modeling are absolutely true and can accurately determine the cause of the derailment. The simulation experience not only enhances the UM software abilities, but also created models allow to simulate lon-gitudinal dynamic processes of all train running regimes.