The Simulation Study On Correct Use And Misuse Of Child Restraint System In Vehicle Frontal Impact

In China, the number of private cars is rapidly growing, but it does not increase public attention to child safety. This is mainly due to that the research on safety protection for child occupant is not widely carried out. The safety standard for child occupant safety has not been established. Since the 70’s, Europe and other developed countries began to research protection of the child restraints; most developed countries have built strict regulations and industry guidelines for their production. Therefore, learn mature experience from developed countries and improve the level of domestic research on child restraint system is of great significance.In addition to the child seat itself can provide adequate protection for children, whether the child seat can correctly and stably be installed in the car seat is the key of the child safety. In this paper, several common child seat fixtures on the market are simulated for analysis and evaluation: Firstly, based on the ECE R44 frontal impact sled test, a child restraint system simulation model of 3-year-old dummy was established and the model was validated by test results. On this basis, six computer simulation models of child seat installation were built: (1) use three-point seat belts to install child seat, without top tether; (2) use LATCH to install child seat, without top tether; (3) use ISOFIX to install child seat, without top tether; (4) use three-point seat belts to install child seat, with top tether; (5) use LATCH to install child seat, with top tether; (6) use ISOFIX to install child seat, with top tether. Comparing the kinematics and dynamic responses of the dummy to analyze the effect of the different fixtures to children’s injury; Secondly, nine models in the condition of misuse were built for evaluating the misuse risk of the different installation; finally, the installation of child seat continued to be analyzed when the child seats were installed toward rear to further understand the influence of fixed installations to children’s injury.The results showed seats using LATCH and adults’seatbelt with top tether had similar protection effect on children. In the case of seat using LATCH without top tether the injury risk was highest. The seats using rigid ISOFIX anchorages generally produced lower forward head movement; the head resultant acceleration was lower than other anchorage types, the injury risk appreciably increased in the condition with top tether than without top tether. The misuse rate of ISOFIX was lowest. For the flexible connection, the top tether had great effect on the protection of child seats. Considering misuse rate and the protection for children, ISOFIX performed better.