平曲线上大调整量弹性支承块式轨道结构动力响应规律分析

Analysis of dynamic response law of elastic support block rail structure with large adjustment on flat curve

基于车辆-轨道耦合动力学及有限元方法,采用ABAQUS®-MATLAB®联合仿真技术,建立车辆-钢轨-弹性支承块式无砟轨道耦合动力学模型,研究不同的车辆类型在多种平曲线线型条件下大调整量弹性支承块式无砟轨道的动力响应特性,分析并评估弹性支承块式无砟轨道用于小半径曲线线路条件的适用性和可行性。研究结果表明:轨下垫板高度的调整对各项指标的影响比支承块帽檐高度调整对各项指标的影响小,当调高从-60 mm增加到60 mm时,轨距扩大量增幅达到了235.00%,当且仅当在调低或调高轨下垫板高度时,轨距扩大量才会发生明显变化;随曲线半径减小,轨距扩大、行车安全性、稳定性等指标随之增大;小曲线半径对支承块的轨距保持能力具有较大影响,当半径减小到2 800 m时,轨距扩大量相比于半径5 000 m的增大了67.50%;与客车相比,当货车运行至小半径曲线路段时,轨距扩大量具有明显的增大趋势,在相同运行条件下,相比于客车的轨距扩大量,货车的轨距扩大量增幅达到110.45%。总体而言,在不同曲线半径、支承块调高情况下,列车运行各项安全性、稳定性及轨距扩大量等指标均在规范规定的安全限值以内,总体来看轨道几何保持能力良好;在实际工程中,当列车尤其是货车经过小曲线半径路段时,应尽量降低行驶速度,以避免困难路段所带来的影响行车安全性、稳定性等隐患。

Based on the vehicle-track coupling dynamics and finite element theory,ABAQUS®-MATLAB®co-simulation was introduced to establish the vehicle-rail-elastic support block type ballastless track coupled dynamics model,the dynamic response characteristics of elastic support block type ballastless track with large adjustment under various horizontal curve conditions for different vehicle types were studied,and the applicability and feasibility of elastic support block type ballastless track for horizontal curve conditions were analyzed and evaluated.The results show that the adjustment of the height of the under-rail pad has a greater impact on various indicators than the adjustment of the height of the support block brim.When the height increases from-60 mm to 60 mm,the increase in gauge expansion reaches 235.00%,and there is a significant change in gauge expansion,only when the pad height is lowered or raised.With the decrease of curve radius,indicators such as gauge expansion,driving safety,and stability also increase.A small radius of the curve has a significant impact on the gauge retention ability of the support block.When the radius decreases to 2800 m,the gauge expansion increases by 67.50%compared to that of a radius of 5000 m.Compared to passenger trains,when the freight train reaches a small radius curve section,there is a significant increasing trend in gauge expansion,in the same operating conditions of the truck's gauge expansion compared to the passenger car,the increase reaches 110.45%.Overall,with different curve radii and support block height adjustments,all safety and stability indicators of train operation,as well as gauge expansion,are within the limits specified in the standard,and the track geometry has a good ability to maintain.In practical engineering,when trains,especially freight trains,pass through small curve radius sections,the driving speed should be reduced as much as possible to avoid hidden dangers such as affecting driving safety and stability caused by difficult sections.