TOPOLAGOM – Optimisation of rail surface topography

Developing a tool to assess how the surface of the rail should look after optimal rail grinding.

Goal

The aim of this project is to develop a tool to assess how the surface of the rail should look after optimal rail grinding.

Additional goals are as follows:

• To characterize the topography of rail surfaces from several locations in the Swedish railway system and connect it to grinding and passage history
  
• To develop a damage index that describes the risk of damage to the rail surface
  
• To develop a calculation model that calculates the damage index based on a given topography
  
• To find optimal topography based on a cost and service life perspective.

Project status and results

The aim of this project is to develop a tool to assess how the surface of the rail should look after optimal rail grinding. Grinding is carried out regularly to prevent crack growth and surface damage to the rails. This is ultimately a safety issue as serious accidents can occur if the rail surface is damaged too much. It would be best if the grinding takes place often and that as smooth a surface as possible is obtained. But this causes both accessibility problems and is very costly. Therefore, it is important to be able to assess whether a surface is good enough so that as few grinding operations as possible can be carried out without affecting safety.

In this project, we will develop a method which can predict the deformations and local stresses that arise in the contact between wheel and rail, due to the surface structure (topography) from the rail surface.

Based on these results, we will develop an index that describes the risks of fatigue and wear. We will also artificially generate a large number of topographies and calculate the damage index for these. This data set can then be used to train a so-called artificial neural network (ANN). This ANN can in principle be used directly when inspecting the rails but can also be used to search for optimal topography if both damage risk and grinding cost are included as parameters, i.e., it will be possible to find a suitable balance between them. We believe that the project's results potentially can provide to significantly reduce maintenance costs.