Effect of Service Speed on Dynamic Response of Heavy-Load Depressed Center Flat

Abstract

In order to study the dynamic response characteristics of depressed center flat car with different velocity, based on multi-body system dynamics software SIMPACK, 320t depressed center flat car system rigid body and rigid-flexible coupling-body dynamics model were established and the dynamic response simulation analysis of empty and loaded flat was carried out under several velocities. Then maximal vertical vibration displacement amplitudes and vertical vibration accelerations of depressed centre flat frame under different velocities were obtained. It showed that the maximum accelerations and displacements amplitudes increase 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 because the elastic vibrations from the depressed center flat frame and all levels of suspension contribut to the vertical displacement. As the speed increases, the vertical displacements of the rigid-flexible coupling-body and the elastic ones response synchronously. The vertical displacements of the empty and heavy vehicles reach their peak values at different speeds and the elastic displacement also has a large proportion, which shows that there are larger elastic vibrations at the speeds. Therefore, it is not suitable for the depressed centre flat to run at very high speeds, and the speed should be confined.