Vehicle Child Restraint System Safety Testing Evaluation And Statistical Data Analysis

Road traffic accident is one of the most import factors causing the death of child occupants.In China,more than 18,500 children under the age of 14 die in traffic accidents every year.With the development of automotive safety technology,as well as children's security problem gradually be taken seriously,child safety has become an important topic in automotive safety research.Domestic child safety research started late,child restraint system(CRS)of regulation is not perfect and product quality imperfection of direct impact on the safety of child occupants.In this paper,based on the literature research,the computer simulation method and the statistical analysis method are used to study the injury risk of 3-year-old child occupant in sled test under different impact acceleration and the child restraint system's child occupant safety.In order to obtain the sled crash acceleration defined in the FMVSS213 regulation.The finite element(FE)method and sled test method were employed to fit the lengths,thickness and diameters of the thin-walled circular tubes and different weight of the sled device.The influence of the acceleration pulses on the kinematic and injury parameters of the 3-year-old child were performed using Q3 dummy FE model seated in the two types of 5-point harness child restraint seat(Seatbelt and ISOFIX)whose were loaded the obtained FMVSS213 and exist ECE R44 acceleration pulses.The simulation results demonstrate that the kinematic of the Q3 FE model was 20 ms earlier using FMVSS213 test acceleration than that in the ECE R44 test.The head forward displacement,HIC15,head acceleration and chest acceleration is high using FMVSS213 test acceleration compared to the ECE R44 acceleration.The neck axial force and chest deflection were similar in two test conditions,however,the neck axial force were larger than the injury assessment reference value(1705N).The research result shows that the safety requirement of CRS in the FMVSS213 is higher than that in ECE R44,this result could be benefit for revision of child restraint system security standards in our country and research of the CRS design.This article through the different manufacturers of child seat 3C certification test,the development of child seat test and the market dynamic test of child seat test data statistical analysis found that cross-group products in the statistics of child restraint system occupies a large proportion.The quality of the restraint system is mainly distributed in 4~10 kg.At the same time,the P3 test of group I was the most difficult to pass the regulation in the collision test,and the head displacement of children was the main factor in the failure of the child restraint system.The results show that in the group I test ISOFIX with the fixed way to effectively restrain the seat movement,the dynamic response from the dummy can be seen in the smaller seat angle flip,the 5-point seatbelt restraint the better,the dummy head displacement is smaller.For group II P3,P6 dummy tests,ISOFIX can effectively reduce the dummy head displacement,but for group III P10 dummy test,ISOFIX effect is not obvious,instead may increase the head displacement.The use of 3-point seatbelt restraint dummy,the belt can effectively limit the dummy pelvic movement,but the dummy in the process of physical movement caused by the shoulder strap easy to fall off,in reality may be on the occupants of the abdomen and arm serious strangulation.This study can provide reference for the evaluation of child injury and the design of child restraint system.