Research On The Safety Of Car Rollover Crash And Occupant Response

The statistics indicated that although the vehicle rollover accident accounts for a small proportion in all road traffic accidents,the great personal injuries caused by the large deformation in the roof,the large roll acceleration and collision force in a rollover accident are quite serious,so its casualty rate is relatively high.What’s more,with the decreasing of the front and side impact accidents,the proportion of rollover accident shows a gradual increasing trend.In addition,the international regulations on vehicle rollover crash aspect are really scarce,meanwhile rollover crash tests have not been included in the scope of the testing in C-NCAP,so research on vehicle rollover crash’s safety is of great significance for reducing occupant injuries under the conditions of rollover accidents and improving the structural safety of the car.The paper firstly uses finite element softwares to analyze the upper structures’ strength of the car according to the mandatory regulation of FMVSS 216 and the provisions of SAE J996,but the simulation results show that the intensity do not meet the regulatory requirements,so the optimal design schemes of the upper structures are raised.Then in order to achieve the purpose of further raise the upper structures’ strength,some important parts are optimized based on the shape and size by using optimization software―HyperStudy.Secondly,the vehicle’s rollover safety under the condition of ADAC Corkscrew test is studied by using HyperMesh and LS-DYNA softwares.The main contents include: first of all,establish the occupant restraint system finite element model of dummy,three-point seatbelts and seat,next coupled them with the car and test the validity of all the models;following this,build the finite element model of the car spiral rollover crash and conduct dynamic rollover simulation;finally analyze the safety of the car under climb the single step ramp and second ramp,meanwhile the results before and after optimization from the aspects of roof deformation and vehicle acceleration,as well as the personnel’s injuries in the rollover are also analyzed.Then the safety of a certain type of car in a common condition―Curb trip rollover test is studied.The contents are as follows: firstly,establish the simulation model of vehicle curb trip;then the car’s rollover safety is analyzed from the aspects of car’s trip turned trajectory,roofdeformation,rollover crash acceleration and energy changes,at the same time analyze the roof deformation and vehicle acceleration before and after optimization;in the end,evaluate personnel’s injuries in the rollover case from various parts of the dummy.Finally,conclusions of this study are achieved and suggestions are put forward to the follow-up work.The results of this paper provide a reference to further improve the car rollover crash safety and protect occupants.