基于轴桥柔性的100%低地板车动力学分析

Dynamic Analysis of 100%Low Floor Vehicle Based on Axle Bridge Flexibility

为了研究独立旋转车轮转向架簧下轴桥的弹性特性对整车动力学性能的影响,以某型100%低地板车整车为研究对象,在建立其多刚体模型的基础上,考虑轴桥的振动弹性特性,进一步建立了3模块整车刚柔耦合动力学模型。在轨道随机不平顺激扰下开展整车动力学性能对比分析,发现刚柔耦合模型较多刚体模型轮轴横向力和脱轨系数升高,轮轨垂向力和轮重减载率降低。轴桥振动响应的计算结果表明,刚柔耦合模型的轴桥横向振动响应较多刚体模型幅值降低约15%;轴桥弹性特性分析结果显示,当轴桥结构垂向自振频率在15~25 Hz之间时,其模态振型会被轮轨动态作用激发,从而对整车动力学性能产生较大影响。在此研究基础上,开展了轴桥结构的轻量化设计,在保证整车动力学性能的约束条件和结构强度的前提下,优化了其几何截面并将其质量降低了约15%,在一定程度上为100%低地板车的轴桥设计提供了工程借鉴。

In order to study the influence of elastic characteristics of the unsprung axle bridge of the independent rotating wheelset bogie on the dynamic performance of the whole vehicle,a certain type of 100%low-floor vehicle is taken as the research object,based on the establishment of its multi-rigid body model.Considering the vibration and elastic characteristics of the axle bridge,one three-module rigid-flexible coupling dynamic model of the whole vehicle is further established.A comparative analysis of vehicle dynamic performance is carried out under random track irregularities.Compared with rigid body model,it is found from rigid-flexible coupled dynamic model that the wheel-rail lateral force and derailment coefficient is increased.the wheel-rail vertical force and wheel unloading rate is decreased.Calculation results of the axle-bridge vibration response show that the axlebridge lateral vibration amplitude of the rigid-flexible coupling model is reduced by about 15%to the rigid body model.Results of the elastic characteristics analysis of the axle-bridge show that the vertical vibration frequency of the axle-bridge structure is 15~25 Hz.The mode shape will be excited by the wheel-rail dynamic action,which will have a great impact on the dynamic performance of the vehicle.On the basis of this research,the lightweight design of the axle bridge structure is carried out,under the premise of ensuring the constraint conditions of the dynamic performance of the vehicle and the structural strength.The geometric section is optimized and its mass is reduced by about 15%.To a certain extent,providing engineering reference for the axle bridge design of 100%low-floor vehicles.