Analysis Of The Kinematics And Head Injury Of Two-wheelers In Vehicle Collisions Based On Accident Video Records

As vulnerable road users,two-wheelers are extremely vulnerable in traffic accidents.With the development of automobile safety technology and traffic management,the two-wheelers fatalities in traffic accidents have fallen,however,the overall fatalities and injuries numbers are higher.It is complex that cyclist kinematics and injury comparison with pedestrian,until now there has been no effective regulation for cyclist protection.This problem cannot be ignored while development of the protection countermeasures.In china,more than 3.7 billion bicycles and 2.5 billion ebikes exist in China now.The rapid increasing of the bicycle-sharing leads to a great challenge for cyclist protection in the traffic situation with mixed transportation mode.Therefore,the issue of automobile safety technology for the two-wheeler need to be more concerned.The purpose of this study is to investigate the characteristics of the two-wheeler accidents based on the accident videos and establish the database for the two-wheeler accidents video information.On the basis of the video result analysis,the kinematics and injury mechanism of rider under different parameters were deeply understood by multi-body model and finite element model.It can provide reference for the active and passive protection design of the rider in the future.Firstly,200 two-wheeler traffic accident videos were selected from VRU-TRAVi(VRU-Traffic Accident Videos)and the database for the two-wheeler accident video information was established based on the codebook of CIDAS.With the advantage of the video information,the paper analyzed the kinematics of rider before/during/after the collision.The results showed that the most common occurrence of two-wheeler accidents were at the intersection,and approximately 60% of cases represented a collision case where the car hit the side of the two-wheelers.In the two-wheeler accidents,53% of the riders made an emergency posture before the collision,and 25% of the riders maintained their normal posture.In addition,we found that the road vehicle may be an important factor causing the driver's visual obstacle.The driver's vision in 42% of accidents is affected by other vehicles on the road.The multi-rigid body model is an important tool for studying rider injury meachism.A classical accident case was selected to reconstruct and made parametric study by this accident reconstruction based on the accident video analysis.It aims to investigate the influence of different parameters on the kinematics and head injury of the riders.The results showed that the vehicle velocity and impact position were important factors for the kinematics and head injury.Finally,the effect of vehicle maneuver on the kinematic and injury risk of the cyclist cannot be ignored while development of the protection countermeasures.One hundred cyclist accidents with video information were analyzed to investigate the vehicle steering maneuver during emergency braking before collisions occurred.The vehicle steering effect was summarized as the parametric analyses of the cyclist kinematic and diffuse brain injury risk by employing THUMS ver.4 occupant and OFO bicycle-sharing finite element models during a bonnet type vehicle collisions.The finite element parametric simulations showed that the vehicle steering had a greater effect on the cyclist head contact location in lateral than that in longitudinal direction.The brain diffuse axonal injury risk of cases having steering maneuver was higher than those of having no steering maneuver.