直线段货车脱轨原因的仿真研究

Computer simulation study on the mechanism of derailment of freight car on tangent track

采用 5 0个自由度的货车 -轨道非线性耦合动力学模型 ,仿真计算了计入轨道弹性的典型空货车非线性蛇行运动规律 ,指出非线性蛇行运动存在着临界速度和转变速度 ,分别对应着蛇行运动的不同状态。研究了摇枕与侧架抗菱刚度、一系纵向刚度对非线性蛇行转变速度的影响。研究了不平顺对直线段货车脱轨稳定性的影响 ,结果表明波长 6～ 8m的方向不平顺和波长 4～ 6 m的高低不平顺引起较大的脱轨系数和减载率 ,使脱轨危险性增大。计算和测试结果在规律上具有很好的一致性 。

Computer simulation of hunting motions of Chinese conventional empty freight car on tangent track is carried out. A nonlinear 50 degree of freedom vehicle track coupling dynamics model taking account of track elasticity is applied for the simulation, which makes the simulation results more realistic. The results show that there exists, for nonlinear hunting, critical speed and transition speed corresponding to different state of motions. The influence of different vehicle structure parameters on the transition speed of nonlinear hunting is studied, and parallelogramming stiffness and longitudinal stiffness of primary suspension are found to be the controlling factors. Meanwhile, the influence of track geometry irregularities on the stability of derailment is investigated. The results show that irregularities of alignment with wavelength in the range of 6~8 meters may cause large derailment quotients and rates of wheel load reduction and hence increase the risk of derailment; the similar results are obtained for irregularities of longitudinal level and the most unfavorable wavelength range is 4~6 meters. The simulation results presented in this paper have good correlation with the test results, and show the mechanism of freight car derailment on tangent track from the point of view of both vehicle structure and track status.