有轨电车特小半径曲线受力和变形特性

Mechanical and Deformation Characteristics of Extra-small Radius Curve for Tramway

根据有轨电车轨道结构特点,采用有限元软件建立钢轨-道床三维空间耦合力学模型,研究曲线半径、曲线长度对无缝线路受力和变形特性的影响。研究结果表明:由于无缝线路和下部基础均为连续结构,在最大温度荷载作用下,曲线段支承层带动无缝线路向外臌曲变形,且在相同圆心角条件下,曲线半径越大,支承层变形量越大,无缝线路受到直线段挤压越显著,从而形成折角;反之,半径较小对无缝线路受力和变形更有利,但此时会限制有轨电车允许通过速度,延长通过时间,影响交通,应综合考虑。常用荷载作用时,钢轨受力和变形仅随圆心角的增加而逐步减小,与轨温、作用点、半径无关,建议选用较大圆心角,以降低横向力对无缝线路受力和变形的影响。

According to the characteristics of track structure of tramway,a three-dimensional spatial coupling mechanical model of rail-track bed was established by using the finite element software,and the influences of curve radius and curve length on the mechanical and deformation characteristics of CWR were studied.The results show that,due to the continuous CWR and base structure,the curved track structures deform outward under the action of maximum temperature load.Under the condition of the same central angle,the larger the radius of the curve is,the greater the deformation of the supporting layer will be,and the curved track structure is easily squeezed by the straight track structure and forms sharp bend at the straight-curve dot.Although the small radius of the curve is more favorable for the stress and deformation of CWR,but it will limit the travelling speed of tramway,extend the passage time,which will influence traffic at intersection,so all the factors above should be considered at tramway route selection design.Under common load case,the stress and deformation of the rail decrease gradually with the increase of the central angle,which are not related to rail temperature,load point and radius.It is suggested that the larger central angle should be chosen to reduce the influence of lateral force on the stress and deformation of CWR.