A Study On Motorcyclist's Head Responses And Brain Injuries During Impacts Against Vehicle

Motorcycle to vehicle collision is one of the most common types of accidents in the world and usually leads to serious or fatal head injuries to motorcyclists.This study aims to investigate the influences of impact scenarios and vehicle front-end shape parameters on head injury risk of the motorcyclist.Five general types of vehicles were selected for a parametric analysis,including Sedan,MPV?Multi-Purpose Vehicle?,SUV?Sport Utility Vehicle?,SEV?Small Electric Vehicle?and 1-BOX vehicle.Impact scenarios were set according to ISO 13232 regulation considering impact angles and impact speeds.In this paper,combined with multi-body system and finite element numerical simulation method,the head injury risk of motorcyclist in front collision between motorcycle and vehicle was studied in detail.The main research achievements are:?1?A FE model of an ABS motorcycle helmet was established.The crash experiments of different parts of the helmet were carried out to verify the FE model of the helmet.The MBS?Multi-body System?model and FE?Finite Element?model of motorcycle-vehicle collision were established respectively,the windshield of five existing vehicle finite element models was refined in this paper.The improved model is closer to the real situation.?2?Through the MBS simulation,the process of the front collision between the motorcycle and vehicle as well as the dynamic responses of the motorcyclist's head were studied,and the impact position distribution of motorcyclist's head was analyzed.The influence of vehicle speed,head-to-vehicle impact speed,impact angle,impact position and vehicle front-end shape parameters on the dynamic responses of the head were revealed.The results show that most of the head impact positions are located on the hood or windshield.The HIC₁₅5 as well as angular acceleration exceeds the threshold and rises rapidly when the collision speed exceeds 15 m/s,while the critical speed for CSDM is around 10 m/s.The head injury risk of the motorcyclist during 90°collision is higher,0°is relatively lower.Bonnet length shows obviously higher effects on head injuries compared with other vehicle front-end shape parameters.The shorter the bonnet length,the greater the HIC₁₅,angular acceleration and CSDM.?3?Through the finite element simulation,the brain injuries of motorcyclist were studied.The effects of head-to-vehicle impact speed,head impact position,impact force and the use of helmet on brain injuries were revealed.The results show that the correlation between head-to-vehicle impact speed and von Mises stress or first principal strain is stronger than that of brain pressure and skull stress.Coup pressure and skull stress are more sensitive to head impact force than von Mises stress and first principal strain.When colliding at high speed,helmet shows a clear effectiveness on reducing brain pressure and skull stress,while its influence on von Mises stress and first principal strain is small.When colliding at low speed,helmet may aggravate head injury.