重载列车车钩力对列车偏载安全性影响

为了分析偏载列车在小半径曲线运行的安全性问题，基于重载列车纵向动力学模型和短编组三维重载车辆轨道耦合动力学模型，对偏载车辆的安全性指标进行了分析. 首先利用纵向动力学模型分析了重载列车纵向冲动时的车钩力特征和变化规律，其次将计算得到的车钩力作为边界条件输入到三维短编组重载车辆轨道耦合动力学模型，研究了小半径曲线运行时车钩力和车辆偏载量对列车安全性指标的影响. 研究结果表明:单编万吨列车的最大车钩压力随着车位的增大而减小；货车向外侧偏载时，钩压力对偏载货车安全性影响较大，钩拉力影响较小. 当钩压力增大到800 kN和车辆偏载量增大到500 mm时，轮重减载率将会增大到1.00，因此，制动工况更容易出现偏载脱轨事故；相同偏载量下，曲线外侧偏载下的轮重减载率比内侧偏载情形的大；当钩压力由0增大至800 kN时，由轮重减载率确定的横向偏载量安全限值由?421 mm降低至?215 mm，设定重载列车偏载的安全限值的时候应考虑纵向冲动的影响或制动加速度量的控制. 

Effect Analysis of Coupler Force onHeavy-Haul Train Safety Under Eccentric Loads

To analyze the safety of the train under eccentric loads running on a small-radius curve track, its safety indexes are analyzed, on the basis of the longitudinal dynamic model of heavy-haul trains and a 3D dynamic train-track coupling model with short marshaling. First, with the use of the longitudinal dynamical model, the characteristics of the coupler force and its variation law are analyzed; and the calculated coupler force is taken as a boundary condition in the 3D dynamic coupling model to analyze how the coupler force and eccentric distance affect the safety indexes in the course of the train running on a small-radius curve track. The results show that for the 10 000 t train, the maximum coupler pressure decreases with the train sequence. When the eccentric load is outward, the coupler pressure greatly affects the train safety, but the coupler tension has little influence. When the coupler pressure reaches 800 kN and the eccentric distance 500 mm, the wheel weight reduction rate rises to 1.00. Therefore, with eccentric loads, derailment accidents are more likely to occur in braking conditions. With the same eccentric load amplitude, the wheel weight reduction rate under the outward eccentric load is higher than that under the inward eccentric load. When the coupler pressure increases from 0 to 800 kN, according to the wheel weight reduction rate the limit of the lateral eccentric distance decreases from ?421 mm to ?215 mm. This demonstrates that the longitudinal impulse and braking acceleration should be considered when designing the safety limit of the heavy-haul the train.