Systems Modelling

Modelling experts at Corus use a suite of models that can be run independently or together as a powerful tool. The models include:

• Vehicle dynamics model – providing accurate prediction of wheel forces and the contact patch positions.
• Global track model – a mechanistic model that reacts to loading and predicts bending stresses. An excellent tool for ‘what if?’ studies encompassing vehicle loads, track geometry, component type and support conditions. The model includes representation of ballast and sub-grade and models the in-service conditions of track components including rail, sleepers and rail pads.
• Contact stress model – predicts the contact stresses at the rail surface and the distribution through the rail head. Models wheel/rail contact and has been developed to analyse residual stresses, strains and crack initiation in rails. The tool comprises two finite element analysis models and can determine stresses in both the wheel of the vehicle and the rail.
• Rolling contact fatigue model – a crack initiation and growth model for rolling contact fatigue. It can estimate fatigue initiation life for given traffic conditions, track quality and rail grade. Also predicts crack growth following initiation.

The suite of models, in conjunction with practical understanding of rolling contact fatigue through site monitoring, enables the development of analytical fatigue life models. These can be used by track engineers to support decision-making for optimum rail maintenance strategies – such as grinding – and rail renewal programmes.