路基不均匀沉降对地铁A型车辆动力学特性影响研究

Effects of subgrade uneven settlement on dynamic characteristics of metro type A vehicles

路基不均匀沉降会导致轨道变形,进而映射到钢轨造成轨面不平顺,对行车安全和运行平稳性带来影响。针对城市轨道交通整体道床典型轨道结构,基于车辆-轨道耦合动力学理论,建立考虑轨道自重荷载和轮轨接触关系的车辆-整体道床无砟轨道空间耦合动力学实体模型,分析了路基不均匀沉降条件下车辆行驶速度、路基不均匀沉降波长和幅值等参数对车辆动力学特性的影响。分析结果表明:随着车辆行驶速度和路基沉降幅值的增大,车辆系统动力学响应也响应增大,当速度超过85 km/h时对行车安全性和舒适性均造成不利影响,且路基不均匀沉降引起车辆动力学响应的敏感幅值为30 mm;路基沉降波长对车辆动力学特性的影响呈先增大后减小的变化规律,其中在波长为20~30 m时对车辆动力学特性影响最为显著。

Subgrade uneven settlement leads to track deformation,and further rail surface is not smooth to have an impact on driving safety and running stability.Here,aiming at typical track structure of urban rail transit,based on the theory of vehicle-track coupled dynamics,a vehicle-monolithic ballastless track coupled dynamic model considering rail self-weight load and wheel-rail contact relation was established to analyze effects of vehicle speed,subgrade uneven settlement wavelength and amplitude on vehicle dynamic characteristics under the condition of subgrade uneven settlement.Results showed that with increase in vehicle driving speed and subgrade uneven settlement amplitude,the dynamic response of the vehicle system increases;when vehicle speed exceeds 85 km/h,it has a harmful effect on vehicle running safety and comfort;the sensitive amplitude of the vehicle dynamic response caused by subgrade uneven settlement is 30 mm;the effect of subgrade settlement wavelength on vehicle dynamic characteristics firstly increases,and then decreases,within the wavelength range of 20-30 m,the effect is the most significant.