Abstract: In order to study the dynamic response characteristics of depressed center flat car, based on multi-body system dynamics software SIMPACK, 320 t depressed center flat car system rigid body and rigid-flexible coupling-body dynamics model are established and the dynamic response simulation analysis is carried out. Then the acceleration dynamic response results of selected points in the chassis under different velocities are obtained and are compared with the experimental data. The results show that the maximum acceleration increases with as the speed gradually increased for both empty and heavy vehicles and the trends are similar for the rigid body or rigid-flexible coupling-body. But the values of rigid-flexible coupling-body are bigger than that of rigid body. At the same time, the average acceleration of the trend is consistent with the test results and the values of rigid-flexible coupled model are closer to experimental ones, indicating that the rigid-flexible coupling model is better than the rigid one and more reasonable. In addition, the dynamic response of heavy vehicle is bigger than that of empty one.

Key words: Heavy load, Multi-body dynamics, Rigid-flexible couple, Simulation