Study on side impact responses of suspension module in trams

The finite element models (FEM) of a 5-module 100% low-floor tram and a city bus are established to study the responses of trams under side impact scenarios. The model is a low-floor tram impacted vertically on the side wall of its suspension module. The simulation is conducted under two scenarios, one is the tram impacted by a Movable Deformable Barrier (MDB) with the velocity of 50 km/h, and the other one is the tram impacted by the city bus with the velocity of 30 km/h respectively. The result shows that three main responses of side impact are the lateral traverse, rolling and yawing displacements of the tram body. There are also failure of lateral stop, wheelset uplift of bogie and plastic deformation of sidewall on the impact side. The responses of tram in the latter collision scenario were more severe than those in the former. Rational explanations may concern that the kinetic energy of the city bus is bigger than the MDB, and the height of the impact point of the city bus is higher than that of the MDB. The result also indicates the damage in tram accident with large and medium automobiles, such as buses and trucks, is more severe than smaller cars. By analyzing the side impact problems of trams, the result can contribute to the development in side crashworthiness designs and the establishment of side impact standards for trams.