On train speed reduction in circumstances of thermally-induced railway track buckling

• Published in: Engineering failure analysis 2018-10, Vol.92, p.107-120
• Main Authors: Yang, Guotao, Bradford, Mark A.
• Format: Article
• Language: English
• Subjects: Dynamic analysis; Railway track buckling; Safe speed; Speed reduction; Weinstock criterion
• ISSN: 1350-6307; 1873-1961
• DOI: 10.1016/j.engfailanal.2018.02.009

Increasing heatwave spells associated with global warming profoundly affect the propensity of continuously-welded railway tracks to buckle laterally in a horizontal plane. Train derailments in the presence of buckled tracks endanger the community and are costly to repair. Track buckling is a localization phenomenon, and the amplitude of the buckle increases in the post-buckling range. Because of this, it may not be possible for a train crew at speed to observe a small buckle, or indeed to stop the train if a larger buckle is encountered. There is, therefore, a need to be able to assess the derailment vulnerability as a train passes over a buckled railway track. This paper proposes a finite element modelling of passenger cars and the required speed reduction in circumstances in which railway buckling has occurred. The model of the passenger car is composed of three parts - a carriage, bogies and wheelsets - being connected by springs and dampers. The response of the passenger car is obtained by adopting implicit dynamic analysis, with the analysis being undertaken in the presence of four buckled configurations obtained from non-linear structural analysis. The Weinstock derailment criterion is invoked to describe the vulnerability to derailment, and the derailment index so calculated is shown to increase significantly with the train speed. The effects of the buckle amplitude, the rail size and the ballast resistance on the safe speed are investigated, with the amplitude of the buckle being shown to be the most significant parameter at a particular speed. •Effects of track buckling on train derailment•Influence of four buckling modes is investigated.•Railway tracks with different characteristics are analysed.