基于车辆-轨道单元的桥上CRTS Ⅱ型板轨道竖向振动分析

Analysis of vibration characteristics for elevated CRST Ⅱ slab track based on vehicle- track element

根据车辆与桥上CRTS II型板轨道结构相互作用的特点,提出一种车辆单元与一种轨道单元,运用有限元方法和Lagrange方程,建立2种单元的动力有限元方程。车辆单元与传统车辆模型的不同在于每个车轮下附有一系钢轨,该钢轨仅用于车辆与轨道之间的耦合,不计其质量和刚度。利用这种车辆单元,可建立运行车辆与轨道结构耦合的显示算法,避免了复杂的程序编制工作。基于轨道参振作用,轨道单元从形式上表现为扣件间距范围内的一段轨道截矩,涵盖了钢轨、扣件、轨下垫板、轨道板,混凝土连续底座板、桥面板以及相互作用的4层梁模型。计算结果与文献对比表明,基于车辆单元与轨道单元的车辆—轨道—桥梁耦合振动模型及其程序能够反映轨道结构的振动特性以及进行相应的动力性能分析。

According to the characteristics of vehicle - CRST II slab track - bridge coupled interaction, a new type of vehicle element and track element were proposed. Finite element method and Lagrange equations were utilized to establish the dynamical finite element equations of these two elements. The difference between the new vehicle element and traditional one is that below every wheel there is a section of rail. And this rail is only used for the coupling between vehicle and track without considering its mass. Using this vehicle element, the explicit algorithms of moving vehicle - track coupled interaction can be built. In this ease, it avoided complicated programming work. Considering the track structure vibration effect, the track element which is a cut section within the fastening- spacing and includes corresponding rail, fastenings , elastic pads, track slab, concrete base layer and bridge deck as well as a four - layer beam model of their interactions. Based on vehicle element and track element, the vertical vibration model of vehicle - track - bridge coupled system can be established. Specifically, the model proposed in this paper shows high performance in the numerical examples of previous research. The model verification indicates that the vehicle - CRST Ⅱ slab track - bridge coupled model based on vehicle element and track element and its relevant numerical programs can be used to analyze and reflect the railway track structure dynamic behavior.