Tailoring a Three-Layer Track Model to Delay Instability and Minimize Critical Velocity Effects at Very High Velocities

The aim of this paper is to tailor the geometry and material parameters of a three-layer railway track model to achieve favorable properties for the circulation of high-speed trains at very high velocities. The three layers imply that the model should have three critical velocities for resonance. However, in many cases, some of these values are missing and must be replaced by pseudocritical values. Since no resonance occurs at pseudo-critical velocities, even in the absence of damping, deflections never reach infinity. By using optimization techniques, it is possible to adjust the parameters so that the increase in vibrations remains minimal and does not pose a real danger. In this way, circulation velocities could be extended beyond the critical value, thereby increasing network capacity and consequently improving the competitiveness of rail transport compared to other modes of transportation, contributing to decarbonization. The presented results are preliminary and require further analysis and validation. Several optimization techniques are implemented, leading to designs with already rather high pseudo-critical velocities. Further research will show how these theoretical findings can be utilized in practice.