车辆系统的多个蛇行运动

摘要

采用升速法和降速法对复杂非线性轮轨接触关系下车辆系统的分岔行为进行研究，发现系统存在运动幅值相差不大的两个蛇行运动解并存的现象，这种多个蛇行运动解并存的特性与一般的由单个亚临界 Hopf 分岔所引起的稳定定常运动与稳定蛇行运动并存的特性有所不同，很容易使车辆在相应速度附近运行时由于扰动的不同而使摆振幅值往复变化，影响车辆的正常安全运行，因此临界速度测定时需要在多种可能的激励条件下多次测试综合分析。%The bifurcation behaviors of a railway vehicle system with a complex nonlinear wheel-rail contact relation were investigated using the methods of increasing speed and decreasing speed.It was shown that two hunting motions with similar amplitudes coexist in the system;there are some differences between the coexistence of multiple hunting motions and the coexistence of the stable steady motions and the stable hunting motions caused by a single sub-critical Hopf bifurcation in the railway vehicle system;the coexistence of multiple hunting motions may easily cause the reciprocating change of the vehicle's shimmy amplitude due to different disturbances to affect the normal and safe operation of the vehicle;therefore,the critical speed should be determined through comprehensive analysis under various kinds of possible excitations and multiple tests.