Wheel-rail contact models in the presence of switches and crossings

Abstract

Multibody codes are widely used to model and study the operation of railway vehicles on realistic track, where the wheel-rail contact model is the key to represent the vehicle-track interaction forces. However, the development and implementation of wheel-rail contact models in multibody codes remain two active research topics, aiming at improving the accuracy of numerical results and computational efficiency of the dynamics analysis. The realism of numerical results is challenged when considering switches and crossings (S&C), where the most adverse wheel-rail contact conditions occur. This paper presents a benchmark study where the performance of the multibody codes MUBODyn, VOCO and VI-Rail are assessed using three case scenarios that involve typical contact conditions observed in S&C. A focused description of the relevant methods to determine the wheel-rail contact forces is presented for each software. The three scenarios considered in this work have been designed to represent typical challenging contact conditions observed in S&C, i.e. conformal contact, contact with a sharp edge, and impact loads. The scenarios proposed in this work are fully described, making them easily reproducible. The agreement between results is discussed in the framework of the methods implemented in each code. This work highlights the impact of wheelrail contact methods on the results as well as on the computational efficiency of the multibody codes.

Wheel–rail contact model for railway vehicle–structure interaction applications: development and validation

“…Fig. 26 Marker and line styles assigned for the experimental and numerical results, respectively, with respect to each span length • The second validation example consists of evaluating the lateral stability of a single wheelset running at several speeds. The dynamic response of the wheelset calculated with the proposed model is compared with that obtained using a semi-analytical model with two degrees of freedom available in the literature.…”

“…In this work, the position of the contact point is also determined online, but based on intersection volumes, i.e., the contact point location is determined based on the farthest points belonging to the intersection of the contacting surfaces that define the wheel and rail profiles. More recently, Magalhaes et al [26] proposed a complex and comprehensive online contact model able to detect multiple contact points in switches and crossings scenarios, while Sun et al [27] used an alternative offline contact approach based on lookup tables to efficiently detect contact points in hunting stability scenarios. These models, however, are restricted to multibody simulations and cannot address the response of the structure.…”

Parametric analysis of railway infrastructure for improved performance and lower life-cycle costs using machine learning techniques

“…The maximum train-track loads are obtained by computational simulations [76][77][78][79] considering conventional railway vehicles with axle loads of 15, 19 and 22 ton. For each axle load configuration, three train speeds are considered as detailed in Table 2.…”

On the use of transmissibility for the detection of damaged springs in the primary suspension of a locomotive

“…Computer simulations using the multibody code MUBODyn 28 are used to study the dynamic behaviour of the vehicle under nominal and damaged conditions. MU-BODyn allows to model the wheel-rail contact, [29][30][31][32] and includes several kinematic joints, force elements, imperfect kinematic joints, 33 and a library of normal and friction contact force models 34,35 that are suitable to represent the railway dynamics. In what follows, the transmissibility concept and the LTDI method are described, being followed by the results section, where the case study is presented, and the results are discussed.…”