基于边界约束刚度参数优化的轨道扣件弹条防断裂设计方法

为了研究弹条服役状态下模态频率与波磨激励频率一致引发的共振断裂问题,建立潘得路FC快速弹条有限元简化模型,通过以弹簧为边界条件模拟弹条不同部位的约束,分析其模态频率随约束刚度的变化规律,提出基于弹条约束刚度参数优化的防断裂设计方法。结果表明:弹条扣压端垂向约束刚度(150～450 N/mm)对弹条第一、三阶模态频率(400、900 Hz)有显著的正相关作用,并对第三阶共振峰幅值有明显影响;弹条后跟下部径向约束刚度(400～1 600 N/mm)的变化,引起弹条第二阶模态频率(660 Hz)的变化,两者呈现正相关关系,同时对弹条第二阶共振峰幅值也有显著影响。弹条第二、第三阶模态频率为危险频率,防断裂设计时应重点考虑。

Anti-fracture Design Method of Rail Fastening Clip Based on Boundary Constrained Stiffness Simulation Technique

In order to study the resonance fracture caused by the modal frequency and the excitation frequency of corrugation in the service of the fastening clip, the finite element simplified model of the Pandrol Fastclip is established, and different parts of the fastening clip are simulated by using the spring as the boundary condition to analyze the variation law of the modal frequency with the change of the constraint stiffness. An anti-fracture design method based on the optimization of the stiffness parameters of the fastening clip is proposed. The results show that the vertical restraining stiffness of the front end of the fastening clip(150～450 N/mm) has significant positive correlation with the first and third-order modal frequencies(400, 900 Hz) of the fastening clip, and also has significant influence on the third-order resonant peak; the change of the radial restraining stiffness of the lower part of the fastening clip(400～1 600 N/mm) results in the change of the second-order modal frequency(660 Hz) with positive correlation between the two and also has significant effect on the amplitude of the second-order resonant peak. The second and third modal frequencies of the fastening clip are dangerous frequencies, which should be addressed in the design of the anti-fracture.