Research On The Sled Test Method Of Car Seat In Offset Impact

According to statistics,the probability of full frontal impact and offset impact is higher in all kinds of traffic accidents.As the vulnerable group in road traffic accidents,the child passenger's safety has attracted people's attention.The research on child passenger's traveling safety started relatively late in China,and there is little attention to the safety performance of car seat under offset impact for the regulation standards and evaluation methods of car seat at domestic and abroad.Therefore,it is of great significance to study the child passenger's traveling safety under offset impact.At present,the offset impact research is mainly based on the vehicle test,but the vehicle test cost much and time-consuming,so this paper is devoted to using the sled test to simulate the vehicle test and doing some research on the car seat:1)This paper analyzes the cases involving child passengers in the database of National Automobile Accident In-Depth Investigation System(NAIS),and summarizes the relationship between the child passenger's injury characteristics and the crash overlapping rate,crash speed.The results show that the proportion of child passengers is higher in full frontal impact and 40% offset impact.Data support for offset impact sled test is provided below.2)The vehicle test of offset impact was carried out,and the damage situation of Q3 child dummy under the offset impact of real vehicle was obtained.Selecting a domestic common car seat,according to the impact method of 64km/h 40% offset impact in C-NCAP,the movement and key parts damage situation of the dummy were obtained.3)The CAE model of the sled test is established to determine the boundary condition of the sled test.First of all to scan the car seat of the vehicle test and establish the car seat finite element model,then establish sled model,harness belt model,and verify the validity of this system.By adjusting the two parameters of the sled rotation angle and acceleration waveform,the simulation results are compared with the vehicle test results,so as to selectthe optimal solution.The results show that when the sled rotates 10 degree and the acceleration waveform of the side sill beam of the dummy is scaled by 80%,the simulation result of the sled test is closest to the result of the vehicle test.4)The sled test was carried out to verify the simulation results.Carry out the sled test by the sled rotation angle and the acceleration waveform of simulation,comparing the injury characteristics of Q3 dummy with the vehicle test results to verify the effectiveness of the simulation results;and on the basis of sled test results under offset impact with the GB full frontal impact sled test results were compared,analyzing the differences among them.The results show that the sled test method can well reproduce the vehicle test under offset impact;the chest acceleration of dummy under offset impact is much higher than that of full frontal impact.Sled test method for car seat under offset impact can greatly reduce the number of vehicle test,reduce research costs,shorten the development cycle and has high practical value,at the same time can provide reference for development of car seat regulations.