Nonlinear Finite Element Modelling of Railway Turnout System considering Bearer/Sleeper-Ballast Interaction

Abstract

Rail turnouts are built to enable flexibility in the rail network as they allow for vehicles to switch between various tracks, therefore maximizing the utilisation of existing rail infrastructure. In general, railway turnouts are a safety-critical and expensive feature to a rail system as they suffer aggressive operational loads, in comparison to a plain rail track, and thus require frequent monitoring and maintenance. In practice, great consideration is given to the dynamic interaction between the turnouts components as a failed component may have adverse effects on the performance of neighbouring components. This paper presents a nonlinear 3D finite element (FE) model, taking into account the nonlinearities of materials, in order to evaluate the interaction and behaviour of turnout components. Using ABAQUS, the finite element model was developed to simulate standard concrete bearers with 60 kg/m rail and with a tangential turnout radius of 250 m. The turnout structure is supported by a ballast layer, which is represented by a nonlinearly deformable tensionless solid. The numerical studies firstly demonstrate the importance of load transfer mechanisms in the failure modes of the turnout components. The outcome will lead to a better design and maintenance of railway turnouts, improving public safety and operational reliability.

New Insights from Multibody Dynamic Analyses of a Turnout System under Impact Loads

“…However, the P1 portion of the impact induced wheel forces could be higher [36,44,45] than this threshold, but they are mostly acceptable as the duration of the impact is small. As aforementioned, both numerical studies and field measurements [7,11,32,40] show that the highest contact forces and vertical accelerations of the wheelsets are observed at the crossing panel, particularly at the crossing nose. The common insight in these studies is that the most critical part of a turnout is the crossing panel.…”

“…As discussed, most of the previous studies are focused on the wheel-rail interface. There also exists other research interest on turnout components such as sleepers and bearers [31,32]. Nevertheless, these models apply the simple moving load approach with a dynamic impact factor to simulate the worst-case scenarios of loading conditions over the turnout.…”

Torsional Effect on Track-Support Structures of Railway Turnouts Crossing Impact

“…The finding confirms that the crossing panel is where turnout bearers experience the greatest bending moment and shear force (Iwinicki et al, 2009). Despite a large number of investigations, there exists no report on torsional effect on damages of turnout components in the real world (Sae Siew et al, 2015). A highlight of this study is the torsional effect on the turnout structure where improved resiliency will help suppress such an important effect (Kaewunruen, 2012(Kaewunruen, , 2014cNimbalkar et al, 2012).…”

Dynamic Performance of Concrete Turnout Bearers and Sleepers in Railway Switches and Crossings

“…In practice, the lateral force is moderated by alignment and geometry design to be less than 20% of vertical force and the anchorage of fastening has been designed to take care of such the lateral actions [12,13]. In fact, field measurements suggest a diverse range of sleeper flexural behaviors, which are largely dependent on the support condition induced by ballast packing and tamping [14][15][16][17]. However, it is still questionable at large whether modern ballast tamping process is effective and it could enable adequate symmetrical support for sleeper at railseat areas.…”