高速铁路道岔曲形轨件弯制特性及疲劳性能

Bending Process Characteristics and Fatigue Performance of Curved Rail Parts for High Speed Railway Turnouts

以曲基本轨、曲尖轨、叉跟尖轨、短心轨和翼轨五种轨件最大弯折处为研究对象,分别测定其极限载荷下断裂瞬间的最大位移载荷和表面最大应变,对轨件弯制点进行了疲劳校核,并根据五种轨件断裂时挠度和载荷以及应变-挠度关系提出了五种轨件侧向弯制许用最大挠度。结果表明:对于五种曲形轨件,断裂时短心轨表面最大应变最小,为125491×10-6,翼轨表面最大应变最大,为251872×10-6;曲形轨件经过反复弯制后,极限强度没有明显下降,但极限实时挠度下降4.1%~43.0%,反复弯制对钢轨安全冗余量有较大影响;曲形轨件在服役载荷下能够满足弯曲疲劳性能要求。

The maximum bending points of five types of rail components,namely curved basic rail,curved pointed rail,forked heel pointed rail,short center rail,and wing rail,were taken as the research object.The maximum displacement load and surface maximum strain at the moment of fracture under ultimate load were measured,and fatigue verification was carried out on the bending point of the rail components.Based on the deflection,load,and strain-deflection relationship during fracture of the five types of rail components,the allowable maximum deflection for lateral bending of the rail components was proposed.The results show that for the five types of curved rail components,the maximum strain on the surface of the short center rail is the smallest during fracture,which is125491×10-6.The maximum strain on the surface of the wing rail is 251872×10-6.After repeated bending,the ultimate strength of the curved rail did not significantly decrease,but the ultimate real-time deflection decreased by 4.1%~43.0%.Repeated bending has a significant impact on the safety margin of the steel rail.Curved rail components can meet the requirements of bending fatigue performance under service loads.