Research On Head And Neck Injury And Protection Of Three-year-old Children's Occupants In Side Collision

In recent years,due to the rapid growth of the number of motor vehicles and private cars in China,the occurrence of various types of traffic accidents is still rising,but the research on the damage of children occupants in traffic accidents is not deep enough,most of the collision safety research for children is in the front and back collision conditions,but the proportion of side collisions in traffic accidents is also larger.Because of the large physiological characteristics of the child's head and the soft neck,even with the child restraint system,large damage may occur in side collisionsAccording to the boundary conditions of vertical side collision conditions in C-NCAP,combined with the collision form of side collision traffic accident statistics,this paper adopts three different angles of collision conditions of 30°,60° and 90°.The side impact point is consistent with C-NCAP,the impact point is obtained by moving R point 250mm in the negative direction of X axis.In the three collision conditions,CRS fixed by ISOFIX and three-point seat belt fixed by vehicle are selected respectively.The selected child occupant model includes the Q3 child dummy model and the THUMS 3YO child finite element model.Based on the overall side impact model constructed by the above basic model,the head and neck injuries of child occupants in side impact from three different angles are studied with Q3 child dummy at first,and then the characteristics of head and neck injuries of children are analyzed in detail with THUMS 3YO child finite element model,Finally,the structure of the child safety seat was improved by adding a child's neck inflatable balloon,and the effectiveness of the protection measure was exploredThe results show that there are some differences in the protection effect of the same CRS when colliding at different angles,and two different fixed types of CRS also show different protection effects when colliding at the same angle.When the collision angle is small,the head acceleration and neck force of children are smaller.When the collision angle increases,the head and chest acceleration and neck force increase.When the collision angle is 60°,the head and door collision of children in CRS B increases the risk of injury.For different types of CRS,there is a certain amount of relaxation in the three-point seat belt.In the process of collision,the neck force is smaller than that of ISOFIX CRS.The improved two CRS have obvious protective effect at 30° and 60°collision angle.The damage values of head and neck are lower than the damage tolerance.At 90° collision angle,the axial tension of the neck of the child crew increases greatly,which may be caused by the mismatch between the structure of the neck balloon and the pillow and skeleton of CRS,or the large amount of gas in the neck balloon,and the relationship needs further study.In the course of the study,a brief analysis was also made on the chest injury of the child occupants.The research shows that the chest acceleration of the child occupants is relatively higher than that of the frontal crash under the same boundary conditions,which is far beyond the value of the chest injury stipulated in the regulations.The main reason for the chest injury value is that during the collision,the child will have an impact on the side of the CRS,which has a greater impact on the child's chest.Further research is needed.