Simulation And Optimization Of Top Airbag Based On Detached Child 's Working Condition

Currently, the restraint system used on most cars are based on the normal position of use of adult development, while ignoring their children’s posture smaller the damage caused by the airbag in the high-speed expansion process will result in off-site child skull, spine, sternum, etc. damage. Since the off-site crew pose randomness and complexity in the study to protect the occupants from the position requires a lot of tests, in order to reduce research costs and improve the efficiency of research, the need for research and experimental simulation method of combining. However, due to off-site research is needed to establish a precise simulation model to simulate the real balloon to expand the balloon shape, and therefore the need for airbag models fold correctly to obtain accurate reference grid, accurately simulate the entire air bag deployment process, these are the simulation of bits from technical difficulties.The article from the domestic and foreign research methods Child was elaborated by comparing US and European safety regulations in different systems, the choice of the US FMVSS 208 regulations as the study of children aged 3 passenger side head and thorax airbags from the bit position close to children off-site simulation basis. Through the introduction of multi-body system MADYMO software with finite element model, using the Folder module MADYMO airbag is folded, and the establishment of an airbag based on computational fluid dynamics model algorithm using an initial proof method. On this basis, the establishment of three-year-old child dummy in OOP (Out of Position) model, and simulation and static and static airbag deployment tests were compared by analysis of the airbag cover to tear process, verify that the more rigid body-mixed finite element the accuracy of the model. Secondly, through the analysis of the actual vehicle on the standard conditions given dummy injury criteria for airbag optimized parameters below provide the basis for occupant protection.Select the airbag volume scaling factor S, airbag weaving discouraged coefficient C, airbag weaving density ρ, airbag deployment angle θ four parameters were optimized by orthogonal design method to determine the final optimized parameter values. The results showed that:by increasing the air bag X、Y scaling factor to the increase coefficient can be discouraged weaving for children 3 years old chest near the dashboard, the dashboard close to the head of state two dummy lowered head, chest neck injuries, but for the chest close to the dashboard child dummy, reduce initiation angle helps reduce injuries, and for child dummy head near the dashboard, adding airbag deployment angle but more conducive to reduce the damage.For children 3 years old and close to the chest position status dashboard, standard value I3 damage optimized than before optimization 21.1%; former standard I3 value for 3-year-old child’s head injury in a position close to the state of the instrument panel, optimized ratio optimization increase by 25.7%. Based on the child dummy head, neck, chest injury analysis, the head injury criteria HIC15, neck, pulled axial force Fz, chest and chest compression D synthesis cumulative 3ms acceleration a3ms were FMVSS 208 regulations Caps inside, you can see, the optimized airbag, can effectively reduce the damage to the 3-year-olds, give full play to the role of off-site protection of children. Via regular adult occupant posture improved contrast based on adult injury after balloon comparative analysis shows that the improved airbag not only from the Child played a protective effect, but also effectively reduce the adult normal posture of the neck, chest injuries, for off-site research has development and application value.