轨道不平顺作用下动车组安全运行速度限值研究

Research on Safe Operation Speed Limits of EMU under Irregularity

为研究无砟轨道轨向和高低不平顺对车辆-轨道耦合系统的动态影响,确定各不平顺值下的限速标准,分别建立CRH2A型车和CRH5型车计算模型。通过3σ原理将不平顺样本的10 m弦测值拟合为正态分布,取其μ±3σ的值为该样本不平顺值。计算不同速度等级、不同程度高低和轨向不平顺值时,两种车型的动力响应。研究结果表明:多数工况下CRH5型车所确定的不平顺限值小于CRH2A型车,说明CRH2A型车动力学性能更优;轨向不平顺主要引起车辆横向扰动,高低不平顺主要引起车辆垂向扰动,说明某方向上的不平顺激励主要对同方向造成扰动;列车对于横向的激励较垂向激励更为敏感,因此轨向不平顺限值通常要小于高低不平顺限值;计算得到各动态不平顺值对应的限制速度,利用轨道动静态几何不平顺之间的关系转化得到各速度等级下轨道静态几何尺寸容许偏差管理值,对规范内容有一定的补充。

In order to research the dynamic effects on vehicle-track coupling system under the influence of track alignment and profile irregularities and determine the speed-limiting standards,vehicle-track coupling model of CRH2 A and CRH5 high speed trains are built. The value of 10 m chord measurement of irregular sample is fitted to the normal distribution,and is taken as the value of this sample based on principle. The dynamic responses of the two models at different speeds and various degrees of irregularities are calculated. The results show that the irregularity limit of CRH5 is less than that of CRH2 A,which indicates that the dynamic performance of CRH2 A is better than that of CRH5. The alignment irregularities mainly cause vehicle lateral disturbance,and the profile irregularities mainly cause vehicle vertical disturbance,which demonstrates that irregularities in one direction will only cause disturbance in the same direction. Trains are more sensitive to lateral excitation than to vertical excitation,therefore,the alignment irregularity limits are generally less than the profile irregularity limits. The speed-limiting standards of different dynamic irregularities are determined and tolerance values of static irregularities are calculated based on the relationship transformation between dynamic and static irregularities,which is supplementary to the code.