Improving Child Safety Seat Performance Through Finite Element Simulations

In this study, a finite element (FE) model of a child seat was developed. This model along with a HIII 6-year-old child ATD model was validated against four sled tests with different restraint conditions under FMVSS 213 test environments. The simulated results of ATD kinematics and restraint forces correlated well to the test data. In order to reduce the weight of the child seat while keeping its safety performance, different design concepts were explored by FE simulations with a mesh morphing method. It was found that lowering the height of child seat base can effectively reduce the weight and head/knee excursions in frontal crashes at the same time. Reducing the material in low stress areas would reduce the weight but slightly increase the ATD head and knee excursions in crashes. Overall, the modified design with reduced based height and reduced weight in low stress areas has a weight of 1.13 lbs less than the original seat, and the ATD head and knee excursions in FMVSS 213 test conditions with four different restraint conditions all reduced. In addition, it was found that changing the tube shape can potentially change the distribution of the head and knee excursions without much impact on weight. This study demonstrated the feasibility and usefulness for introducing FE simulations into the child seat design process. Future studies using this validated FE child seat model should focus on other crash scenarios, such as those with different impact severities and directions to improve safety performance of the child seat design.