轨道结构落轴冲击动态响应有限元分析

通过确定落轴冲击问题的轮轨接触条件,根据接触冲击响应的虚位移原理,将轮轨接触边界条件用罚函数法释放,确立轮轨接触变分方程;采用点面接触单元导出轮轨接触有限元控制方程,进一步建立轨道结构动力有限元方程,从而可模拟计算落轴冲击对轨道结构产生的动态响应。基于该分析方法,求解了弹性支承块轨道结构的动力性能,并由现场实测得到验证。结果表明,运用所建立的落轴冲击有限元计算模型分析轨道结构动力性能,直观有效。

Railway Track Structure Dynamic Response under Wheel Load Drop by Use of FEM

According to the virtual displacement principle for contact-impact problems, the equation on calculus of variations about wheel-rail contact is developed as its determined boundary conditions being released based on the penalty way. Depending on the contact control as well as the track dynamic equation of FEM deduced from the point-to-surface contact element, the dynamic response is simulated and calculated for the railway structure impacted by the falling wheel-set. The dynamic characteristic of the low vibration track is investigated on the basis of this analyzed method, which is verified by the on-the-spot experiment. The results show that it is more intuitive and effective to study the track dynamic performance by the presented wheel-load-drop FEM model.