PhD Research by Haoyu Wang
Ivan Shevtsov, Rolf Dollevoet, Valeri Markine
02/01/2010 - ongoing
High Speed Tracks
FEM, high speed, railway, track transition, VGS,
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Transition introduces discontinuity in vertical stiffness of the rail which results in increase of the dynamic forces and deterioration of track geometry due to track settlement on the embankment side. The track maintenance costs in the transition zones are consequently increasing. This problem becomes more severe in case of high speed lines.
The project aims in finding measures for both prevention and correction of the track geometry deterioration in the track transition zones. The dynamic interaction between railway vehicle and train in the transition will be analysed numerically using 2D (DARTS) and 3D (Ansys LS-DYNA) finite element models. Special attention will be given to modelling of ballast settlement behavior and long term effect. The 2D model is relatively fast and allows analysing the dynamic behavior of various design solutions, whereas the 3D model gets the insights on the ballast degradation. The field observations and measurements will be performed to understand the behaviour of track transition zones as well. The measurement tool is VGS (Video gauge system), which allowing recording the displacement of track components.
Using the numerical models and field measurements better understanding of the dynamic processes in transition zones will be gained. Based on that knowledge new track designs and maintenance procedures for transition zones will be developed.
Design improvement will be achieved by optimising the geometrical and mechanical properties of various track solutions for the transition zones. The optimization will be performed using the modern numerical optimisation method called the Multipoint Approximation Method. The method was successfully used for various structural optimization problems.