Study On Safety Of Tram Operated In Shared Right Of Way Environment Under Side Impact Accident

Unlike the traditional railway vehicles,tram usually operates in mixed traffic environment,which determines the diversity and high frequency of crash accidents.Standards and studies at present mainly focus on longitudinal crashworthiness of train,in order to study the responses and occupant-protecting capability of tram under side impact,a 5-module 100%low-floor tram FEM model was established in this paper.4 impact scenarios that a low-floor tram parking on the rail is impacted perpendicularly on the side faces of motor module and floating module by a bus with the velocity of 30 km/h and a MDB(Movable Deformable Barrier)with the velocity of 50 km/h respectively were designed on the basis of refering to experience of side collision in automobile field.By simulating the whole process of above crash scenarios in LS-DYNA this paper found that side impact responses are mainly manifested as the lateral traverse,rolling and yawing displacements of car body,there are also failure of later stopper,wheelset uplift of bogie and plastic deformation of sidewall on the impact side.Responses of bus-impacting scenarios are more severe than ones in MDB-impacting scenarios,the displacements and deformations of floating module are ofen more severe than that of bogie module.This paper also analysed the responses of occupants in bus-impacting scenarios and found that both of the side impact scenarios will cause head injuries of occupants,the occupant in floating module generated whiplash of neck,which can esaily result in severe injury of neck,new design measures such as strengthening side structure,separating seat from sidewall,protecting neck and limiting secondary collision were proposed in this paper to improve the occupant injury.The injury probability of chest and leg are lower in addition.Suggestions on multistage energy absorption system including sidewall,steering buffer and stopper etc.design methords for side impact are provided.Findings of this papaer can help side crashworthiness designs and establishment of side impact standards for tram.