• CN: 11-2187/TH
  • ISSN: 0577-6686

Journal of Mechanical Engineering ›› 2025, Vol. 61 ›› Issue (18): 267-277.doi: 10.3901/JME.2025.18.267

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Study on Reliability of Rack System on Super-slope Bridge of Rack Railway under Extreme Temperature Load

CHEN Zhaowei1, WANG Lang1, LI Shihui1, YUAN Miao1, PU Qianhua1, YANG Jizhong2, CHEN Zhihui2   

  1. 1. School of Mechatronics & Vehicle Engineering, Chongqing Jiaotong University, Chongqing 400074;
    2. Science and Technology Research Institute of China Railway Eryuan Engineering Group Co., Ltd, Chengdu 610031
  • Received:2024-10-15 Revised:2025-03-02 Published:2025-11-08

Abstract: Many rack railways are planned in the southwest mountain areas of China. Due to the undulating terrain in the southwest mountain areas, there are many super-slope bridges in the rack railways; meanwhile, considering the large temperature fluctuation in mountainous areas, the deformation of the rack system and the bridge system is not coordinated, which may lead to unreliable phenomena such as connection failure of the rack system. Aiming at the interaction problem of vehicle-rack (track)-bridge system with super-slope caused by extreme temperature load, based on the theory of train-track-bridge dynamic interaction, considering the dynamic meshing behavior of rack and the nonlinear contact behavior of wheel rail, the research method and dynamic model of vehicle-rack (track)-bridge system with super-slope under extreme temperature are constructed; On this basis, the connection reliability of the rack system under the connection of fasteners and traditional spring bar fasteners is studied, and then the optimization of the rack system is carried out according to the traditional spring bar fasteners, and the safety region of the key parameters of the optimized spring bar fasteners is proposed. The research shows that under the extreme temperature load of minus 45 ℃, the different connection modes of the rack and sleeper have a great impact on the stress of the rack system; When fasteners are used for connection, the maximum stresses of the rack and bolt are 1 095 MPa and 1 980 MPa, both exceeding their material strength; When the traditional spring bar fastener is used for connection, the maximum stress of the rack and bolt is 203 MPa and 38 MPa, which does not exceed the material strength, but the elastic displacement of the rack and sleeper exceeds the allowable range of the traditional spring bar fastener; When the optimized spring bar fastener is used for connection, the reliability requirements of the rack system can be met. The research results of this paper can provide theoretical basis for the early design and later operation and maintenance of China's rack railway.

Key words: extreme temperature, rack railway, spring bar fastener, mechanical properties, reliability

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