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随着铁路无缝线路的广泛应用,由温度压力引起的轨道臌曲(胀轨跑道)而造成的列车脱轨事故大量增加。本文建立了三维空间无缝线路模型,利用有限元方法编制专用程序用于深入研究温度荷载作用下无缝线路的臌曲特性。三维空间无缝线路模型由四个单元组成:用两侧对称薄壁开口断面梁单元模拟钢轨,每个节点有7个自由度;用实体弹性地基梁单元来模拟轨枕,每个节点有6个自由度;用弹性弹簧模拟扣件系统,弹簧有2个自由度;用弹簧单元模拟道床横向和纵向阻力。此外,在轨道模型中,考虑了钢轨单元的几何非线性,和道砟材料引起的道床阻力非线性特征。通过和其他研究的对比分析验证了该三维空间无缝线路模型的正确性。非线性分析结果表明:轨道臌曲是个空间问题,二维钢轨-轨枕模型和梁模型用于分析无缝线路的稳定性时结果偏于保守。
With the extensive application of seamless railway lines, a large number of train derailment accidents caused by rail choking caused by temperature and pressure (expansion rail runway) have been greatly increased. In this paper, a three-dimensional space seamless line model is established, and a special program is developed by using the finite element method to deeply study the warping characteristics of the seamless line under the temperature load. The 3D space seamless track model consists of four elements: the rail is simulated with bilaterally symmetric thin-walled open cross-section beam elements with seven degrees of freedom per node; the sleepers are simulated with solid elastic foundation beam elements, each node has 6 Degrees of freedom; with elastic spring simulation fastener system, the spring has two degrees of freedom; spring unit simulation horizontal and vertical resistance of the track bed. In addition, in the orbit model, the geometrical nonlinearity of the rail element and the non-linear characteristics of the ballast resistance caused by the ballast material are considered. Through the comparison with other studies, the correctness of the seamless line model in three-dimensional space is verified. The results of nonlinear analysis show that the orbital curvature is a spatial problem, and the results are conservative when the two-dimensional rail-sleeper model and beam model are used to analyze the stability of CWR.