Mathematical Modelling

The XiTRACK™ Process uses state of the art computer software specifically devised and developed to simulate and predict railway track behaviour before and after polymer treatment. These programs are based on enhanced 3-Dimensional finite element techniques featuring advanced mathematical models of material behaviour. Three generic categories of simulations are used:

  • Pseudo-dynamic analysis
  • Dynamic analysis 
  • Granular densification analysis

 In the first two of these analysis categories, complete 3-Dimensional modelling of the track is performed using solid based finite elements incorporating non-linear elasticity and elasto-plasticity as appropriate. 

Stress-wave absorbing techniques are used in the dynamic analysis to allow stress wave transmission at the mesh boundaries. In the latter category of simulation cyclic models (incorporating multiple nested yield surfaces) are used to determine densification rates by simulating stress-induced anisotropy through both isotropic and kinematic hardening.

In addition to the enhanced finite element programs, a complete range of additional advanced computer analysis techniques and software are used to determine track response.

  Click Here To See Academic Paper "Advanced Non-linear Dynamic Finite Element Modelling of Railway Track  Behaviour"

Testing

A comprehensive range of laboratory techniques is employed to develop, optimise and verify the reliability and operation of the modelling techniques and software. The XiTRACK Polymer and GeoComposite structures and designs are studied using a variety of methods long before they get anywhere near a real track site; these tests of necessity include careful study of extended mechanical and dynamic performance. The rheological characteristics of the polymer during application are important parameters to understand to ensure predictable and reproducible topographical distribution and penetration into the ballast; these are also extensively evaluated to ensure compliance with designs.