轴箱内、外置车辆轮轴弯曲对轮轨接触的影响

Influence of wheelset bending on wheel-rail contact of vehicles with inside and outside axle boxes

建立三维轮轨接触有限元模型和考虑轮轴弯曲的轮轨空间接触模型,分析轴箱内、外置车辆因轮轴弯曲引起的轮轨接触参数变化规律;采用Hertz接触理论和有限元模型分别求解轮轨接触应力。研究结果表明:随轴重增加,因轮轴弯曲引起的车轮偏角会不断增加,轮对内侧距会随之发生改变,最大变化量不超过2 mm;当轮对横移量分别为[0,6) mm和(9,12] mm时,轮轴弯曲对轮轨接触参数的影响较小;当轮对横移量为[6,9] mm时,轮轴弯曲会导致轮轨接触点位置、等效锥度发生相对明显的变化;当轮对横移量在[0,6] mm内时,轴箱内置和外置车辆计算得到的接触斑形状都近似为椭圆形,Von-Mises等效应力、接触应力大小基本相等。通过与Hertz接触理论比较可知,有限元模型能反映轮轨接触的实际情况。

A three-dimensional wheel-rail contact finite element model and a wheel-rail geometrical contact model taking account of wheelset bending were established respectively. The variation law of wheel-rail contact parameters caused by the wheelset bending for vehicles with inside and outside axle boxes was investigated. Both the Hertz contact theory and the finite element model were used to solve the wheel-rail contact stress. The results show that with the increase of axle load, the wheels’ deflection angles caused by the bending of the axle increase,and the flange back-back distance of the wheelset changes accordingly, the maximum variation of which does not exceed 2 mm. When the wheelset lateral displacement is [0, 6) mm or(9, 12] mm, the wheelset bending has little effect on the wheel-rail contact parameters of the vehicles with inside and outside axle boxes. When the wheelset lateral displacement is between [6, 9] mm, the wheelset bending causes obvious changes in the position of the wheel-rail contact point and the equivalent conicity of the vehicles with inside and outside axle boxes. For the wheelset lateral displacements in the range of [0, 6] mm, the contact patch shapes of two types of vehicle are approximately elliptical, and the Von-Mises equivalent stresses and contact stresses are almost the same.Compared with the contact stress obtained by the Hertz contact theory, the finite element model can reflect the actual situation of wheel-rail contact.