抑制钢轨波磨的梯形轨道结构的多参数拟合与优化

目的研究地铁车辆结构一系悬挂及轨道结构支承刚度和阻尼对梯形轨道小半径曲线钢轨波磨的影响规律,并提出抑制相应区段钢轨波磨的多参数拟合优化方法。方法基于轮轨系统的摩擦自激振动理论,构建梯形轨道小半径曲线段上带有一系悬挂轮轨系统的有限元模型。然后通过复特征值分析,研究地铁梯形轨道小半径曲线段轮轨系统的摩擦自激振动特性。最后开展地铁车辆结构一系悬挂及轨道结构支承刚度和阻尼的参数化分析,采用最小二乘法,对影响不稳定振动的关键参数进行多参数拟合。根据该拟合方程,采用遗传算法进行关键参数的优化匹配。结果在曲线半径为350 m的梯形轨道上,轮轨间因存在饱和蠕滑力,引起摩擦自激振动,在439.02 Hz时,产生了不稳定振动,从而导致了钢轨波磨的产生。影响轮轨间不稳定振动的关键因素为扣件的垂向刚度、横纵向刚度、垂向阻尼和减振材料的垂向刚度。结论当扣件的垂向刚度为36 MN/m、扣件的横纵向刚度1.68 MN/m、扣件的垂向阻尼为2.9 kNs/m、减振材料垂向刚度为5.57 MN/m时,可有效抑制梯形轨道小半径曲线段上钢轨波磨的发生。

Multi-parameter Fitting and Optimization of the Ladder Track to Minimize Rail Corrugation

The work aims to study the influence of the primary suspension of the metro vehicle structures and support stiffness and damping of the track structures about the rail corrugation on the ladder track in the sharp curve,and to put forward the multi-parameter fitting and optimizing methods of minimizing the rail corrugation on the ladder track in the sharp curve at the corresponding section.A corresponding finite element model of the wheelsets-rail system with primary suspension on the ladder track in the sharp curve was constructed based on the theory of frictional self-excited vibration in the wheel-rail system.The characteristics that frictional self-excited vibration of the wheel-rail system occurred on the ladder track in the metro’s sharp curve section was analyzed according to the complex eigenvalue analysis.Based on the finite element model,the parametric analysis was developed about the primary suspension of vehicle structures and support stiffness and damping of track structure.The multi-parameter fitting was carried out about crucial parameters for affecting the unstable vibration by adopting the least square method.In accordance with the fitting equation,the genetic algorithm was adopted for optimization of the crucial parameters.The results show that,on the ladder track with curve radius of 350 m,the frictional self-excited vibration is caused by the saturated creep force between wheel and rail.The unstable vibration occurs at the frequency of 439.02 Hz,which leads to the rail corrugation.The four groups of parameters which have crucial influence are vertical stiffness of fasteners,transverse and longitudinal stiffness of fasteners,vertical damping of fasteners,vertical stiffness of damping materials.When the vertical stiffness of the fastener is 36 MN/m,the transverse and longitudinal stiffness of the fastener is 1.68 MN/m,the vertical damping of the fastener is 2.9 kNs/m,and the vertical stiffness of the damping material is 5.57 MN/m,the possibility of rail corrugation can be effectively suppressed.