考虑齿轮齿条动态激励的山地齿轨车辆-轨道耦合动力学特性分析

Dynamic Characteristic Analysis of Racked Railway Vehicle-track Coupling System with Considering the Dynamic Excitation of Gear-rack Transmission

基于车辆-轨道耦合动力学及齿轮传动系统动力学理论,建立完整的考虑齿轮齿条动态啮合激励的齿轨车辆-轨道耦合动力学理论模型。提出了基于势能原理的齿轮齿条啮合刚度计算方法,并与Simpack自带的225号力元以及有限元法计算结果进行对比分析,表明提出的方法具有良好的精度与效率。基于该动力学模型,分析了轨道随机不平顺激扰下齿轮齿条动态啮合力、齿轮角加速度、轮轨垂向力、车体加速度等动态响应特性,探究了齿条基体挠度变形对齿轨动态响应的影响,揭示了线路坡度以及行车速度对齿轨车辆动力学性能的影响规律。研究结果表明,提出的解析法和有限元法均能反映齿条基体挠度变形对齿轨动态响应低频特性的影响;齿轮齿条啮合力、齿轮角加速度等齿轨啮合动态响应随线路坡度和行车速度的增加而增加;轮轨垂向力和横向力均方根值随运行速度的增加而增加;在分析的10~35km/h速度范围内,各轮对脱轨系数均小于0.8(允许限值),车体垂向和横向平稳性指标均小于2.5(优),满足相关标准对行车安全性与平稳性指标的要求。

Based on the theory of vehicle-track coupled dynamics and gear system dynamics,a complete racked railway vehicle-track coupled dynamics model which considers the dynamic excitation from the gear-rack mesh is established.Especially,the analytical calculation method of the gear-rack mesh stiffness is proposed based on potential energy principle,and the received results are compared with the calculation results from models using the 225 force element in Simpack and the finite element method,respectively.The results show that the proposed method has good accuracy and efficiency.Based on the established model,the dynamic characteristics of the gear-rack mesh force,gear angular acceleration,wheel-rail vertical force and car body acceleration are analyzed.At the same time,influence of the rack flexibility on the dynamic response of the racked railway system is investigated,and the influence law of the slope gradient and vehicle operation speed is also revealed.The results indicate that the finite element method and the proposed analytical method can reflect the influence of the rack flexible deformation on the system dynamic response characteristics at low frequency range.And the dynamic responses such as the gear-rack mesh force and the angular accelerations increase with the growth of slope gradient or the vehicle running speed.Besides,the root mean square of the wheel-rail vertical force and lateral force also increases with the vehicle running speed.It can be also observed that in the speed range of 10-35 km/h analyzed,the derailment coefficient of each wheelset is less than 0.8(allowable limit),and the vertical and lateral sperling indexes of the car body are less than 2.5(excellent),which meet the requirements of relevant standards for driving safety and stability.