重载列车动力学数值模拟

Numerical simulation of impact effect on heavy haul train

为研究列车纵向冲击对车辆运行安全性的影响,首先对缓冲器动力学模型进行了修正,并利用单自由度车辆冲击对缓冲器特性予以验证;然后采用联合模型法和混合模型法,计算了车辆通过曲线时紧急制动工况下车辆的轮轨横向力和脱轨系数,并与独立模型进行对比。计算结果表明:修正后的缓冲器动力学模型能较好地模拟缓冲器的特性曲线;车辆通过曲线时制动力产生的纵向冲动,导致车辆的曲线通过性能和列车运行安全性降低,在车辆系统动力学分析中应考虑车钩力的影响;联合模型中由于车钩采取固定偏转角,导致其计算结果偏小;混合模型中的车钩偏转角随列车运行是动态变化的,因此混合模型更接近实际运行工况。

In order to study the effect of longitudinal impact on vehicle safety, the dynamic model of draft gear was corrected and verified by impact simulation. The wheel-rail lateral force and derailment factor of vehicle passing through curve rail were calculated by using respectively two models: the mixed train model and the combined train model, and their results were compared with those by using single vehicle system model. The results indicate that the characteristic curves can be well simulated by the corrected model of draft gear; the performance of curve negotiating and the vehicle safety are decreased due to longitudinal impact produced by brake, and the coupler force should be considered in studying the vehicle system dynamically. The results of combined train model are smaller than those of mixed train model because of the constant coupler deflection angle assumed in the combined train model. The mixed train model is closer to actual condition because the coupler deflection angle is varying dynamically along with the train running.