Analysis of Vehicle-Bridge Interaction Using Advanced Vehicle Model

In this study, an advanced vehicle model is proposed by considering the wheel size of two unsprung masses in a three-mass vehicle model in the analysis of vehicle-bridge interaction. In this vehicle-bridge interaction system, the vehicle model has four degree-of-freedoms; particularly, the two degree-of-freedoms account for the displacements of two rigid unsprung masses. The size effect of unsprung masses becomes pronounced in the presence of pavement irregularity. Further, the real contact points and lifts of two unsprung masses turn to be unknown parameters in the theoretical formulation. Therefore, a numerical procedure is proposed to locate the two unsprung masses on the bridge such that these parameters can be determined during simulation. With the consideration of the size of unsprung masses, it is shown that the moving paths of two unsprung masses are the envelopes of pavement irregularity. This indicates that the riding comfort can be improved by adopting a larger size of wheel in practical applications.