Model Rail-Guided Systems with Simpack

The Simpack Rail Modules enable the modeling and analysis of any rail-guided system. Typical rail vehicles including high-speed trains, local trains, locomotives, trams and freight vehicles are all commonly modeled in Simpack. In addition, Simpack Rail can also model more exotic rail applications such as roller coasters and suspended railways. Simpack Rail can also model all common track types, including ballasted track, slab tracks, bridges, turnouts and crossings.

Simpack Rail

The Simpack Rail modules offer specialized modeling elements for rail applications allowing the simple modeling of standard vehicle components and infrastructure. Elements are available for the easy modeling of wheelsets, including but not limited to axles with independent wheels, untrue (out-of-round) wheels, friction modifications for flange lubrication, drivetrain or braking dynamics, etc. In combination with standard Simpack elements, an extensive library of specialized suspension elements includes functionality to model shear springs, air springs, helical springs, dampers, friction elements, and bearings.

Arbitrary track layouts including additional local irregularities/imperfections can be defined with an intuitive user interface, inputting data directly or by referencing external track data from other sources (measurements). Track features such as turnouts, crossings, and switches are easily modeled. Varying levels of track complexity from inertia-fixed and elastic track (variable ballast/foundation stiffness) components, to fully flexible track models based on finite element models (see Simpack FlexTrack) can be modeled within Simpack. Rail infrastructure modeling of catenary and overhead contact line structures in contact with the pantograph can also be included in the model.

The Simpack Rail module provides several fast and accurate rail-wheel-contact methods with varying levels of fidelity. Enabling detailed insights into the rail-wheel-contact conditions, including the normal and shear stress distributions of the slip and stick regions within each contact patch.

Simpack FlexTrack

The Simpack FlexTrack (Flexible Track) module allows for the simulation of finite-element-based track sections in Simpack Rail models, allowing for the influence of track/structural flexibility to be included. Flexible Track sections can include anything from short ballast spans of tracks, switches and crossings, to entire structures such as a bridge. Flextrack allows engineers to study not only the influence of track flexibility on the dynamics of the vehicle, but also explore the internal forces on the track structure itself.

SImpack Rail Wear

Simpack Rail Wear is an add-on module to Simpack Rail. The module enables the determination of the distribution across the profiles and the profile changes due to wear. Wheels and rails are subject to wear and rolling contact fatigue (RCF) throughout their lifecycle due to the forces applied by the railway vehicles. This wear leads to maintenance and safety issues. Users can choose between the 'Krause/Poll' and the more detailed 'Archard' wear laws. Since there are so many different wear and RCF laws, the module has an open structure, which gives you the additional possibility to implement your preferred wear and RCF laws.

Simpack Interface to Kalker Contact

Kalker Contact interfaces the advanced rail-wheel contact analysis software CONTACT by Prof. J.J. Kalker and E. Vollebregt to Simpack Rail. CONTACT takes the full local geometries of the wheel and rail into account as well as their relative motion (the normal approach and tangential creepages). It computes the actual non-elliptic contact area, its subdivision into adhesion and slip areas, and the pressures and frictional stresses that occur in the contact patch. This calculation uses a variational approach, which is similar to a finite element method but much faster. It restricts attention to so-called concentrated contacts, using homogeneous elastic materials.

Simpack Interface to Kalker Contact allows the postprocessing of existing simulations with CONTACT. It compares the results in respect to the tangential forces, the contact patch shape, and the stress distribution, which is important for wear and rolling contact fatigue assessment. In addition, Simpack can be used as an easy-to-handle preprocessor for CONTACT. Vtech CMCC is the distributor of the CONTACT library.