Ingår i projekt Gröna tåget / Green train.

In 2004 the research and development program “Gröna Tåget” (Green Train) was initiated in order to develop the next generation of high-speed trains for Nordic conditions, aiming at speeds up to 250 à 300 km/h, still being “friendly” to the track. The purpose with this simulation study is to investigate what measures to be taken in order to modify a bogie that guarantees a stable running behaviour at higher speeds, but still generates acceptably low track forces and amount of wear in curves with smaller curve radii. Simulations are performed with a one-car Regina train modelled in the simulation tool SIMPACK. The simulations have been performed with track geometry cases with varying curve radius, cant and speed (i.e. varying cant deficiency and hence track plane acceleration). The assessment of track forces and ride comfort has been performed on straight track and in curves with radii between 300 and 4900 metres. In order to maintain a stable running behaviour at higher speed the wheelset guidance stiffness of the bogie, as well as the yaw damping, had to be increased, compared with the original design intended for 200 km/h. The purpose of the present study has been to investigate the difference between two different types of bogie configurations with soft and medium wheelset guidance. For comparison, original soft (original Regina for v 200 km/h) and stiff wheelset guidances have been included in the evaluation. The results indicate that the difference between the two bogie types (“soft” and “medium”) is not that evident on straight track and in large-radius curves. However, in small-radius curves the soft bogie configuration generates lower lateral track forces and hence lower energy dissipation (related to wheel and rail wear) than the medium bogie configuration. In the present simulation study the influence of equivalent conicity on the vehicle’s running behaviour has been examined. Ten different contact conditions have been defined, with varying wheel and rail profiles, track gauge and rail inclination. Furthermore, two different types of conicity have been defined, simply called Type 1 and Type 2, where the latter has a high conicity at small amplitudes. Generally, higher values of equivalent conicity generate higher track forces and accelerations. Additionally, simulations performed with conicity Type 2 generally cause higher track forces and accelerations than those with Type 1. During the summer 2006 high-speed tests have been performed on Swedish tracks. A small amount of track force results from these tests have been used in order to validate the simulation model. Test and simulation results show good agreement when studying the track forces in small-radius curves. Also the principal behaviour on straight track shows good agreement.