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| Research on the Expansion Additional Force Algorithm of Continuously Welded Rail on Bridges |
| DAI Gong-lian, ZHENG Rong-rong, CHEN Guo-rong |
| (Central South University, Changsha, Hunan 410075, China) |
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Abstract Abstract：Research purposes： At present, the general resistance model is used to calculate the additional expansion force of rail. When the span is large, it is possible that there is no mechanical solution. In order to obtain an accurate analytical algorithm for the expansion force of the CWR on the bridge under temperature, provide a basis for selecting a reasonable bridge temperature span value and longitudinal resistance, a new algorithm is proposed. In this paper, the nonlinear longitudinal resistance model is used to separate the CWR into several sections according to the position where the fastener enters the plastic deformation zone. A set of equilibrium differential equations is set up to obtain the rail displacement and expansion force. Research conclusions： (1)According to the standard design condition of CWR, the maximum stress of rail and the maximum relative displacement between beam and rail under different longitudinal resistance are calculated.(2)Without considering the braking force, the temperature span limit corresponding to different longitudinal resistance is obtained based on the rail strength limit.(3) Taking 70 mm and 90 mm as the fracture width limit, the minimum value of the line longitudinal resistance is 17 N/(mm·line) and 13 N/(mm·line). (4) The conclusions of this paper can provide the basis for selecting the appropriate temperature span and longitudinal resistance of bridges.
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Received: 17 May 2017
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2017, Vol. 34 
