MODERNIZATION OF THE KNI 140070 VIADUCT AND ITS INFLUENCE ON DYNAMIC RESPONSE UNDER SELECTED HIGH SPEED TRAIN

The paper develops a methodology of FE modelling and simulation of the bridge – track – moving train (BTT) system using LS-DYNA computer code. The KNI 140070 viaduct of span length 14.40 m with ballasted track was selected as a representative for the study. Two variants of the viaduct were taken into consideration – a version operated before the modernization in 2008 and the modernized version including additional flats welded to the bottom flanges of the main beams. The German high-speed train ICE-3 moving at 150–300 km/h was selected. The FE model of the BTT system was developed using Altair HyperMesh and LS-PrePost software. The platform of the viaduct was modelled using 8-node 48 DOF solid elements. The structure was symmetrised, homogenized and reflected by linear viscoelastic orthotropic materials. Discrete model of the track included the main and side rails, fastening systems, sleepers, crushed stone ballast and approach RC slabs. Components of the train FE model were considered as rigid bodies. Cylindrical and revolute constrained joints were applied for kinematic connections and relations between respective components. Discrete springs and dampers were applied for FE modelling of the primary and the secondary suspension systems. Numerical simulations were focused on determining the resonant velocities for both considered variants. Selected time histories for displacements and stresses, were shown as the results of the analyses.