Optimization of high-speed railway track behaviour using genetic algorithms

This paper deals with a multi-objective optimization of geometrical and mechanical properties of a high-speed railway track when subjected to a moving load representative of a train axle. The model of the track employs several simplifications; it was implemented in two dimensions on the explicit dynamics module LS-DYNA for the finite element commercial software ANSYS. The design space is formed by the ballast height and by parameters representing the dynamic properties of the rail-pads. The objective function covers minimization of the maximum ascending and descending displacement and velocity in the main structural elements, namely the rail, the sleepers and the ballast. A genetic algorithm implementation is used to optimize these functions, which proved to be effective in finding quasi-optimal solutions with a low search effort. The tools presented can give insight into how the behaviour of the railway track is influenced by various design parameters.