基于轮对模型的铁道车辆脱轨安全性评估

Derailment Safety Evaluation for Railway Vehicles Based on Wheelset Model

考虑轮对摇头和侧滚运动,推导轮对的三维爬轨脱轨准则,采用轮轴脱轨系数和轮重减载率的联合安全域进行脱轨安全性评估。建立轮对横向和侧滚运动方程,推导轮轴横向力和轮轨垂向力的计算公式。提出一种轮轨力间接测量方法,利用轴箱加速度、一系悬挂相对位移以及转臂应变等测试量,进行轮轨力的反演识别。通过轴箱转臂标定试验,获得转臂定位节点横向力和转臂应变之间的关系。针对某高速客车进行环线线路试验,对比分析测力轮对和间接测量方法获得的轮轨力。结果表明:间接测量方法得到的轮轴横向力和轮轨垂向力与测力轮对波形吻合,峰值误差分别为11.2%和4.3%。直线段的轮轴脱轨系数和轮重减载率均较低,曲线段二者均显著增大,缓和曲线段的轮重减载率逐渐增大而轮轴脱轨系数变化平缓。

Three-dimensional wheel climbing derailment criterion was derived considering the yaw and rolling motion of a wheelset.The safety evaluation against derailment was conducted using the union safety domain of the wheelset derailment coefficient and wheel unloading rate.Lateral-and rolling-equilibrium equations of a wheelset were established to derive the formulas to calculate the wheel axle lateral force and wheel-rail vertical forces.An indirect method for wheel-rail forces measurement was proposed using accelerations of the axle box, relative displacements of the primary suspension as well as strains of the swing arm,to carry out inversion rec-ognition of the wheel-rail force.Axle box swing arm calibration experiments were conducted to obtain the rela-tionship between the lateral force of positioning rubber and the measured strain of the swing arm.Field valida-tion tests were carried out in the Loop Test Line for a high speed passenger train and the wheel-rail forces using this indirect method and wheel-rail forces that obtained from instrumented wheelset were compared.Results showed that the lateral force of axle and wheel-rail vertical force resulting from the indirect method matched the waveform of the instrumented wheelset.Peak errors for lateral axle force and wheel vertical force were 1 1.2%and 4.3% respectively.The wheelset derailment coefficient and wheel unloading rate both stayed low on the tangent track but both increased significantly on the curved track.Wheel unloading rates increased gradually and wheelset derailment coefficients kept steady in the transition curve.