定常气动载荷作用下高速铁路车辆的蛇行运动稳定性

HUNTING STABILITY OF HIGH-SPEED RAILWAY VEHICLE CONSIDERING THE ACTIONS OF STEADY AERODYNAMIC LOADS

  • 摘要: 随着高速列车运行速度的提高,气动载荷会对车辆蛇行运动稳定性带来不利影响,现有文献对此研究很少。为此,考虑沿列车反向运动高速气流以及侧风的作用,研究了定常气动载荷下高速铁路车辆横向运动的线性稳定性。分析中计入了气动载荷改变轴重、使各轮法向支反力各不相同;以及使重力刚度、重力角刚度、轮对蠕滑系数等发生变化的效应。给出了计及气动影响的17个自由度铁路车辆蛇行运动分析模型,编制了相应的计算程序并进行了算例验证。进而,计算了在不同风速条件下,各个方向定常气动力和气动力矩单独以及共同作用时车辆运动稳定性特征值,并求出临界速度。结果表明:气动载荷会降低车辆临界速度;临界速度随横风风速增加而单调降低;与其他方向气动载荷相比,点头力矩和升力对临界速度的影响更大。

     

    Abstract: With the enhancement of the speed of trains, the aerodynamic loads will deteriorate the hunting stability of motion of railway vehicles. There is seldom study on this problem. For this reason, the hunting stability of a high-speed railway vehicle is studied, considering the steady aerodynamic loads resulting from the actions of crosswind and airflow in the opposite advancing direction of train. The effects of variations of axle loads, creep coefficients, gravitational stiffness and angular stiffness due to actions of aerodynamic loads are taken into account. A mathematical model for hunting stability analysis of vehicle with 17 degrees of freedom is presented, in which the effects of aerodynamic loads are incorporated. A program based on the presented model is written and verified. And then, in different wind velocities, with cases for each component of aerodynamic force and moment acting individually and collectively being considered, the eigenvalues of hunting stability of vehicle are calculated. Furthermore, the critical velocities are obtained. It is shown that, aerodynamic loads can decrease the critical velocity of vehicle;the critical velocity decreases monotonously as the velocity of beam wind increases;the influences of pitch moment and lift force on critical velocity are larger than that of other components of aerodynamic loads.

     

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