Research on side impact parameters of child safety seat based on ECE R129 regulation and SIP optimized protection

In this paper, a side impact simulation model is established based on ECE R129 regulations. The four design parameters of headrest stiffness, head cushion foam density, the gap between headrest and dummy head, and seat wing shell stiffness are taken as objects to study their effects on side impact protection of children's safety seats, respectively. And through orthogonal test and variance analysis, the gap between headrest and dummy head and seat wing shell stiffness are selected as optimization parameters. Then, the response surface model of damage index aH and HPC15 is established, and the optimal value is solved by multi-objective optimization method based on NSGA-II algorithm. In order to further improve the side impact protection capability of child safety seat, a side impact model of child safety seat with SIP is built. The influence of structural stiffness, length and installation position of SIP on the side protection performance of child safety seat is studied. Then the optimal design scheme of SIP is obtained by experimental design and comprehensive comparison. It is concluded by above analysis of research that: extending the contact time between the occupant's head and the side wing of the child safety seat can effectively reduce the Y-direction speed of the occupant's head during contact, thus effectively reducing the head injury of children in side impact.