上拱离缝对CRTS Ⅱ型板式无砟轨道动力特性的影响

Influence of Upper Arch Gap on the DynamicCharacteristics of CRTS Ⅱ Slab Ballastless Track

CRTSⅡ型板式无砟轨道上拱离缝在线路中形成了局部不平顺,列车经过时会加剧轮轨之间相互作用,严重时影响行车安全。为研究上拱离缝对车辆-轨道系统动力特性的影响,利用有限元软件建立考虑上拱离缝的车辆-轨道耦合动力学模型,分析不同离缝幅值、离缝长度条件下系统动力响应。结果表明:随着上拱离缝幅值的增加,系统动力响应随之增大,在离缝幅值大于6 mm时,车辆动力响应变化尤为明显。系统动力响应随上拱离缝长度的增加先增大后减小,在离缝长度为6.5 m时最大。列车进入上拱离缝区域后,对轨道结构的垂向加速度和垂向位移影响十分显著,会降低轨道系统的服役性能。

On the CRTS II slab ballastless track,local unevenness is formed due to the upper arch gap,which intensifies the interaction between the wheel-rail and may seriously affect the safety of train operation.In order to study the influence of the upper arch gap on the dynamic characteristics of vehicle-track system,a vehicle-track coupled dynamic model considering the upper arch gap is established by using finite element software,and the system′s dynamic response under different upper arch gap amplitudes and lengths conditions is analyzed.The results indicate that with the increase of the upper arch gap amplitude,the system′s dynamic response increases accordingly,especially when the upper arch gap amplitude is greater than 6 mm,the change in the vehicle′s dynamic response is particularly significant.The system′s dynamic response first increases and then decreases with the increase of the upper arch gap length,and reaches the maximum value when the upper arch gap length is 6.5 m.After the train enters the area with the upper arch gap,the vertical acceleration and vertical displacement of the track structure are significantly affected,which will reduce the service performance of the track system.