Secondary Stiffness of Fastening Clips: Influence on the Behavior of the Railway Track Panel

Abstract

Fastenings are all the materials whose function it is to structurally connect the rail to the sleeper. The fastenings used in concrete sleepers must be elastic in both tension and compression. The basic component of all types of fastenings consists of an elastic steel rod or plate, named spring clip or spring plate. The clip functions as a system with a "compatible" elastic pad. The clip, as a spring, develops the elastic clamping force of the fastening on the rail foot. The load-deflection curve of the clip characterizes the static stiffness of the clip and consequently of the fastening. Some clips present only one type of static stiffness, but the most advanced present a secondary static stiffness also. In resilient fastenings, apart from the clip-acting on the upper part of the rail foot - there is a second spring called the resilient pad, which is made of elastic material compatible with the fastening steel clip, acting under the rail foot. The present study examines the influence of the secondary stiffness of the clip on the behavior of the rail in the track panel in terms of the rail tilt/rotation, the clamping force and rigidity. © ISTE Ltd 2016. All rights reserved.