A RATIONAL METHOD TO DECOUPLE THE TRAIN-BRIDGE INTERACTION PROBLEM Charikleia D. Stoura 1 and Elias G. Dimitrakopoulos 1 1 Hong Kong University of Science and Technology Department of Civil and Environmental Engineering Clear Water Bay, Kowloon, Hong Kong e-mail: cstoura@connect.ust.hk, ilias@ust.hk Keywords: Vehicle-Bridge Interaction, Railway bridge, Dimensional analysis, High-speed rail- ways. Abstract. This paper examines the influence of the vehicle-bridge interaction (VBI) on the vi- bration of railway bridges, and consequently proposes a novel approach to decouple the train- bridge system. Key feature is a dimensionless description of the VBI problem, that reveals the governing parameters of the coupled response and their relative importance. The proposed Modified Bridge System (MBS) approach accounts for the vehicle-bridge interaction effects in- directly, by modifying the mechanical system of the bridge via additional stiffness and damping terms. The study validates the proposed approach for simply supported bridges and a single or a series of traversing vehicles. The analysis indicates that the MBS method outperforms, in all cases examined, the traditional moving load approximation and the Additional Damping Method, while for many cases of practical interest for high speed railways, its results coincide with the coupled solution. 871 COMPDYN 2019 7 th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering M. Papadrakakis, M. Fragiadakis (eds.) Crete, Greece, 24–26 June 2019 Available online at www.eccomasproceedia.org Eccomas Proceedia COMPDYN (2019) 871-888 ISSN:2623-3347 © 2019 The Authors. Published by Eccomas Proceedia. Peer-review under responsibility of the organizing committee of COMPDYN 2019. doi: 10.7712/120119.6965.21325