铰接式岔枕道岔结构落轴冲击数值分析

Numerical Analysis on Dynamic Behavior of Articulated Switch Sleeper in Turnout System Under Wheel Load Drop

摘要:

考虑岔枕下道床的非线性支承和联结铰结构,建立了三维弹性铰链单元数值模拟方法和整组道岔落轴冲击有限元模型,比较分析了时域与频域内铰接式与普通长岔枕道岔结构的振动响应.结果表明:与普通岔枕相比,铰接式岔枕轨道结构的整体刚度较低,缓和了轮轨冲击,改善了道岔区的综合受力环境;改变了普通岔枕的动态特性,极大程度上降低了高速列车过岔时未行车股道岔枕末端对道床的拍击,减少了道砟粉化,延长了道床养护维修周期;道岔区采用高弹性扣件,可与铰接岔枕组合成优良的弹性基础,优化高速道岔动力性能.

Abstract:

Based on the numerical algorithm of a threedimensional flexible joint element to furnish the stiffness and damping in transverse,vertical and rotational directions,a calculation model under wheel load drop according to the finiteelement method is built,and,the dynamic responses in time and frequency domain are studied respectively for a whole turnout structure with articulated or integral switch sleepers impacted by a falling wheelset,considering the nonlinear characteristic of the ballast’s support under the sleepers as well as the special construction of the articulated joints.Compared with the normal integral sleeper design,the track with articulated switch sleepers has a lower rigidity,which changes more evenly along the track and improves its dynamic performance.Furthermore,by modifying the switch sleepers’ vibration behaviour,the articulated joints effectively reduce the impact loading of the ballast at the end of the sleeper under the turnout branch track when the vehicles are running on the main turnout route.This will extend the life of the ballast bed.Finally,in combination with the articulated switch sleepers,high elastic fastenings,whose rational parameters are proposed,are employed to make up the elastic track foundation,the vibration characteristics of highspeed turnout are optimized .