长大列车通过弹性曲线轨道仿真求解方法研究

为解决长大列车与连续长弹性轨道的同步仿真问题，以列车通过曲线轨道为例，采用重载列车-轨道耦合动力学模型，分析了压钩力作用下轨道结构与30 t轴重列车的动态特性，提出了长大重载列车与轨道动态相互作用仿真时模型的简化求解方法.该方法将庞大的列车/轨道耦合振动系统以有限数目的三维车辆模型代替，并考虑其轨下基础结构弹性，从而极大缩减系统运动自由度.研究结果表明:列车可简化为单质点车辆模型和三维车辆模型混合的短编组列车，当模型中只包含一个三维车辆模型，且其前、后车辆均以单质点模拟时，计算结果偏低；列车承受2 200 kN压钩力并通过400 m半径曲线线路时，货车最大轮轨横向力和垂向力较多节三维货车编组模型的计算结果分别低估了24%和4%，钢轨横向、垂向位移则被低估了20%和8%；端部车辆采用单质点模型、中部采用三维车辆模型的车辆数至少为3时，才能较为准确地反映中间目标车辆处轮轨作用力和其下部轨道结构的动态特性. 

Simulation Solution Method for Long and Heavy-Haul Trains Negotiating Elastic Curved Tracks

To solve the synchronisation simulation problem for long trains and continuous elastic tracks, a representative case employing a train curving negotiation is used. A heavy-haul train-track coupled dynamic model is used to analyse the dynamic performance of the track structure with a 30 t axle-load train, when a coupler compressive force is applied to it. As implified principle is presented to simulate the dynamic interaction between the long heavy-haul train and the track. The general concept behind this method is replacing the large train-track coupled dynamic system by a finite number of three dimensional vehicle models, considering the foundation structure elasticity under the corresponding models. Thus, the motion freedom of the system can be significantly reduced.The results indicate that a long train can be treated as a shorter mixed train, composed of a single-mass vehicle model and a three-dimensional wagon model. As only one wagon is simulated by the detailed dynamics model, with the front and rear connected wagons considered as a single-mass model, conservative results are obtained. As the train negotiates a 400 m radius curve, simultaneously bearing a 2 200 kN coupler force, the lateral and vertical wheel-rail forces in the outer wheel of the wagon are underestimated by about 24% and 4% respectively, relative to the results calculated using a train model composed of several three-dimensional wagons. Correspondingly, the lateral and vertical displacement of outer rail are sequentially underestimated by nearly 20% and 8%. When a single-mass model is used at the ends of the train, and the number of the additional wagons simulated by the three-dimensional dynamic model is 3, both the wheel-rail dynamic interaction of the middle target wagon and the track dynamic behaviour, can be reflected accurately.