Reasonable Number of Low Stiffness Rail Pads at Rail Joint Locations

摘要

Based on the theory of vehicle-track coupling dynamics ,a vertical vehicle-track coupling dynamic model is established ,in r which the track is considered as a 3-layer model with sleeper and ballast masses, and the rail is treated as a Timoshenko r beam. To determine the optimal number of low stiffness rail pads at rail joint locations ,the dynamic effect of the number is r investigated. During numerical simulations ,two typical positions of the rail welded joint and two forms of geometric irreg r -ularity are taken into account. The results obtained show that, when the center of the rail joint is just above the sleeper r ,to replace the three or five adjacent rail pads with low stiffness ones is acceptable to reduce the wheel/rail contact force r and the ballast vibration ,and when at the mid-crib, four or six is sufficient.