桥梁错台现象下齿轨-桥梁系统力学性能研究

MECHANICAL PROPERTIES OF RACK RAIL-BRIDGE SYSTEM UNDER BRIDGE MISALIGNMENT PHENOMENON

  • 摘要: 桥上齿轨铁路在服役过程中难免会出现桥梁错台现象,从而导致齿轨变形异常,进而使齿轨和连接部件的局部应力激增,极有可能对齿轨结构造成破坏,最终严重威胁车辆的运行安全与稳定性。该文构建桥梁错台下车辆-齿轨(轨道)-桥梁系统非线性动力相互作用模型,研究齿轨车辆在错台现象下通过大坡度桥梁时齿轨变形、应力、加速度及连接螺栓应力变化规律,并在此基础上提出了桥梁错台的安全控制阈值。结果表明:在齿轮齿轨啮合作用和轮轨作用等多荷载综合作用下,错台现象极有可能导致齿轨连接螺栓发生断裂。针对该文研究参数,桥梁跨中位置处的齿轨最大变形达11.15 mm;当错台量为7.07 mm时,螺栓达到其许用剪切强度;桥梁错台对齿轨振动和应力的影响不大。研究结果可为桥上齿轨铁路设计及后期运维提供理论参考。

     

    Abstract: In the process of service, bridge misalignment phenomenon will inevitably occur in the rack-rail railway, which leads to abnormal deformation of the rack rail, and then to the local stress of the rack rail and connecting parts surge, and it is very likely to damage the structure of the rack rail, and ultimately a serious threat to the safety and stability of the vehicle operation. In this study, we construct a nonlinear dynamic interaction model for a vehicle-rackrail (rail)-bridge system under bridge misalignment, study the deformation, stress, acceleration and connection bolt stress change rule of the rail when the vehicle passes through the bridge with large gradient under misalignment phenomenon, and put forward the safety control threshold of bridge misalignment on the basis of this. The results show that: under the combined effect of multiple loads such as gear rack rail meshing action and wheel-rail action, the misalignment phenomenon is very likely to lead to fracture of rack rail connecting bolts. For the research parameters of this study, the maximum deformation of the rack rail at the mid-span position of the bridge reaches 11.15 mm; when the amount of misalignment is 7.07 mm, the bolt reaches its permissible shear strength; and the misalignment of the bridge does not have much influence on the vibration and on the stress of the rack rail. The study results can be used to provide a theoretical basis for the pre-design and post operation and maintenance of rack railway.

     

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