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H. Magalhães, C. Correa, V. Infante, J. Pagaimo, "Derailment Risk Assessment of a Freight Wagon due to Cyclic Top", in J. Pombo, (Editor), "Proceedings of the Sixth International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Edinburgh, UK, Online volume: CCC 7, Paper 5.14, 2024, doi:10.4203/ccc.7.5.14

Keywords: railway vehicle dynamics, infrastructure, track irregularities, multibody dynamics, wheel-rail contact, unloading indicator.

Abstract

Railway network infrastructure managers ensure safe operations by inspecting and maintaining tracks, adhering to regulations. Track quality is assessed post-inspection, processing track irregularities according to standards. Despite tracks meeting quality criteria, some freight wagon derailments occur. Derailment reports cite cyclic top as an irregularity not covered by standards as the cause of the derailments, however, no clear method to quantify it is provided. This paper aims to develop a robust method for identifying cyclic top. This work considers case studies involving a freight train model from a previous derailment in Portugal and suspected cyclic top track segments. Multibody simulations are performed not only to assess vehicle-track interaction under various conditions, identifying high derailment risk cases using unloading derailment indicators, but also to determine wagon pitch and bounce natural frequencies. Results show a good correlation between high derailment risk, the natural frequencies of the vehicle and the most important frequencies of the track irregularities, which strongly depend on vehicle speed. Thus, it is designed an algorithm to identify cyclic patterns based on track irregularities that is usable by infrastructure managers.

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Front Page Browse CCC CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Conferences ISSN 2753-3239 CCC: 7 PROCEEDINGS OF THE SIXTH INTERNATIONAL CONFERENCE ON RAILWAY TECHNOLOGY: RESEARCH, DEVELOPMENT AND MAINTENANCE Edited by: J. Pombo Paper 5.14 Derailment Risk Assessment of a Freight Wagon due to Cyclic Top H. Magalhães^1,2, C. Correa¹, V. Infante¹ and J. Pagaimo¹ ¹IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal ²Technology Department, MainRail S.L., Pamplona, Spain doi:10.4203/ccc.7.5.14 Full Bibliographic Reference for this paper H. Magalhães, C. Correa, V. Infante, J. Pagaimo, "Derailment Risk Assessment of a Freight Wagon due to Cyclic Top", in J. Pombo, (Editor), "Proceedings of the Sixth International Conference on Railway Technology: Research, Development and Maintenance", Civil-Comp Press, Edinburgh, UK, Online volume: CCC 7, Paper 5.14, 2024, doi:10.4203/ccc.7.5.14 Keywords: railway vehicle dynamics, infrastructure, track irregularities, multibody dynamics, wheel-rail contact, unloading indicator. Abstract Railway network infrastructure managers ensure safe operations by inspecting and maintaining tracks, adhering to regulations. Track quality is assessed post-inspection, processing track irregularities according to standards. Despite tracks meeting quality criteria, some freight wagon derailments occur. Derailment reports cite cyclic top as an irregularity not covered by standards as the cause of the derailments, however, no clear method to quantify it is provided. This paper aims to develop a robust method for identifying cyclic top. This work considers case studies involving a freight train model from a previous derailment in Portugal and suspected cyclic top track segments. Multibody simulations are performed not only to assess vehicle-track interaction under various conditions, identifying high derailment risk cases using unloading derailment indicators, but also to determine wagon pitch and bounce natural frequencies. Results show a good correlation between high derailment risk, the natural frequencies of the vehicle and the most important frequencies of the track irregularities, which strongly depend on vehicle speed. Thus, it is designed an algorithm to identify cyclic patterns based on track irregularities that is usable by infrastructure managers. download the full-text of this paper (PDF, 12 pages, 897 Kb) go to the previous paper go to the next paper return to the table of contents return to the volume description
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