Railway Vehicle Modelling on an Isolated Track Defect of a Cosine Form

摘要

During the motion of a railway vehicle on a rail, with a rail running table/surface of a random form, the rail running table imposes to the vehicle a forced oscillation. Due to different reasons -manufacturing, corrosion, deterioration etc.- the rail's running surface is not smooth but instead it comprises a lot of defects that give to it a random surface in space. Furthermore under the primary suspension of the railway vehicle there are the Non Suspended Masses (N.S.M.) which act without any dumping directly on the track panel. On the contrary the Suspended Masses (S.M.), that are cited above the primary suspension of the vehicle, act through a combination of springs and dashpots on the railway track. A part of the track mass is also added to the Non Suspended Masses, which participates in their motion. The defects with long wavelength, which play a key role, on the dynamic component of the acting loads on the railway track, and consequently -due to the principle action=reaction- on the dynamic component of the reaction of the railway track on the railway vehicle, are modelled and analyzed using the second order differential equation of motion. A parametric investigation is performed for the case of an isolated defect of cosine form.