Showing 2 results for Vehicle-Track Interaction
J. Pombo, H. Magalhães, P. Antunes, J. Ambrósio,
Volume 6, Issue 1 (6-2019)
Abstract
The dynamic analysis of railway vehicles involves the construction of three independent models: the vehicle model; the track model; and the wheel-rail contact model. In this work, a multibody formulation with Cartesian coordinates is used to describe the kinematic structure of the rigid bodies and joints that constitute the vehicle model. A methodology is also proposed in order to create detailed three-dimensional track models, which includes the flexibility of the rails and of the substructure. Here, the finite element methodology is used to model the rails as beams supported in a discrete manner by spring-damper systems that represent the flexibility of the pads, sleepers, ballast and substructure. The inclusion of flexible track models is very important to study the dynamic behavior of railway vehicles in realistic operation scenarios, especially when studying the impact of train operations on the infrastructure and, conversely, the damages on vehicles provoked by the track conditions. This topic has a significant economic impact on the vehicles maintenance and also affects the life cycle costs of tracks. The wheel-rail contact formulation used here allows obtaining, online during the dynamic analysis, the contact points location, even for the most general three-dimensional motion of the wheelsets with respect to the track. The methodology proposed to build flexible track models is validated here by comparing the results obtained with this new approach with the ones obtained with ANSYS. Furthermore, the methodology is demonstrated by studying the dynamic behavior of the Alfa Pendular railway vehicle.
Masoud Fathali, Fereidoon Moghadas Nejad, Hamid Moghadam Ali,
Volume 6, Issue 2 (12-2019)
Abstract
In this study, a new approach for the evaluation of horizontal curve design in railway tracks integrating safety criteria is proposed. To conduct this research, a vehicle-track interaction model is developed in ADAMS Rail program and simulation of dynamic vehicle response from derailment point of view is followed. Using this model, sensitivity analyses are made on the main geometry parameters of horizontal curves, including radius, super-elevation and transition length, considering different speeds. Consequently, the influences of each parameter are investigated on governing derailment criteria i.e. overturning, Nadal and Prud’homme. The obtained results form the basis for further practical charts by which, both the geometry design and safety evaluation of railway horizontal curves can be determined. A practical use of the new approach is finally presented to indicate its capability and applicability.
