A lightweight numerical model of railway track to predict mechanical stress state in the rail

Abstract

a lightweight numerical model of railway track to predict mechanical stress state in the rail maryam el moueddeb 1,2 , françois louf 1 , pierre-alain boucard 1 , franck dadié 2 , gilles saussine 2 , danilo sorrentino 2 1 lmt (ens paris-saclay/cnrs/université paris-saclay), france 2 sncf réseau, france abstract a new approach is conducted within sncf réseau to redefine and improve the current procedure behind rolling stocks admission. a perspective to update computation rules for traffic conditions is to consider track fatigue issues. in this sense, the study aims to provide a better knowledge of stress state induced by moving vehicles in rails through a lightweight numerical model of the track. specifically, the track model consists of a two-layer discrete support model in which the rail is considered as a beam and sleepers are punctual masses. the rail-pads and ballast layer are modelled as spring/damper couples. considering the track's vertical response, the study intends to quantify the impact of the vehicle's dynamic overload on the track response and verify the possibility of these overloads to excite track vibration modes. a first study considering constant moving loads already shows negligible effect of track inertia forces due to high track stiffness and damping. this justifies the prediction of mechanical stress state in the rail for fatigue issues through a static model of the track and a simplified dynamic model for the vehicle.

Experimental Monitoring of Dynamic Parameters of the Sub-Ballast Layers as a Prerequisite for a High-Quality and Sustainable Railway Line

“…A summary of the problems arising within the transition zones, as well as the proposal of alternative solutions based on numerical modeling, is presented in [13], which provides a suitable basis for addressing the issue. The procedure for calculating the dynamic effects of the train passage and the response of the track to the load in question using a numerical model was presented in [14,15]. The specification of boundary conditions (material characteristics), which have a significant influence on the dynamic response of the railway line, was carried out based on the developed numerical model characterized in [16].…”

Experimental Measurement and Simulation of Railway Track Irregularities

“…El-Moueddeb et al have developed a finite element track model subjected to the vertical load of the vehicle. The objective of their simulation was to predict mechanical stress in the rail [11]. A series of research studies have been conducted to analyze the effects of track irregularities on system component behavior.…”