中文摘要：

为了探明机车牵引状态下的横向稳定性，采用多体动力学软件SIMPACK建立了某型提速机车动力学模型，以非线性临界速度作为机车横向稳定性的评判指标，并采用数值积分方法计算了机车临界速度，研究了牵引系数对机车直线和曲线临界速度的影响规律。研究结果表明：机车牵引力的存在改变了轮轨切向蠕滑力的大小和作用方向；随着牵引系数的增大，机车在直线和曲线上的临界速度均先增大后减小；机车曲线上的临界速度低于直线上的，同一牵引系数下，曲线半径越小，临界速度越低；在牵引工况下，轮对横移量不宜再作为机车曲线稳定性的判定指标，采用轮轨纵向蠕滑力对稳定性进行评判更为合理。

英文摘要：

In order to investigate the lateral stability of locomotive under traction condition, a dynamics model of a speed-raising locomotive was put forward by using MBS software SIMPACK. The nonlinear critical speed of locomotive was regarded as the judging index of the lateral stability. The numerical integration method was adopted to calculate the critical speed. The effect of the traction coefficient on the critical speeds was studied, including the speeds on tangent and curved tracks. The result indicates that the traction force influences the value and the direction of wheel/rail creep force greatly. The critical speed increases firstly with the increase of the traction coefficient, and then reduces. The critical speed on curved track is lower than that on tangent track under the same traction coefficient, and the smaller the curve radius is, the lower the critical speed is. It is pointed that the shift of wheelset should not be selected as the judging index of the lateral stability of locomotive, it is reasonable to judge the lateral stability using longitudinal creep force. 8 figs, 13 refs.