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.