Research On Child Seat Safety Performance In Frontal Offset Impact

With the growth of car ownership,the quantity of child occupant is increasing,child occupants as vulnerable groups who are in road traffic accidents,need more security protection device.Study has shown that the correct use of child safety seats can protect children well and effectively.At the same time,road traffic accident research found that Chinese road traffic accident has high frequent and the probability of frontal crash is more than 40%,in all kinds of positive collision angle,offset collision including simulation by sled collision of the probability of traffic accident(60%),and offset collision injury and mortality in the highest.Obviously under the condition of positive bias vehicle impact children’s seat device research on child occupant safety protection has become a key issue.Especially in 2012,our country C-NCAP will offset in the process of collision to test the speed by raising the original 56 km/h to 64 km/h,this subject is put forward to reduce automobile offset collision in the process of children’s deaths crew has the vital significance.We demontoate make a simple statistical analysis to the questionnaire survey about the use of the child seat in the five major cities in the country.According to the research status quo at home and abroad,this paper also research the safety performance of child seat with the situation of the car in the speed of 64km/h and 40% front offset collision,and established a complete child seat restraint system model,use Q3(3 years)child dummy to do a test and use the dummy’s movement pattern,the maximum displacement of the head,the resultant head acceleration changes curve,thorax acceleration curve,the torque curve of neck along the Y axes,pelvis acceleration curves to validate the child seat restraint system model.The results show that the simulation and experimental parameters are consistent,the model can completely and effectively recurrence the characteristics of the test.In the process of simulation,the dummy maximum displacement of the head is 491 mm,3ms thoracic synthetic acceleration is 55 g,the head HIC value is 836.Secondly,it analysis the safety of the child seat under the frontal offset collision and also analysis the damage data and motion process.The analysis found that the important influence factor to reduce the shift of children’s head and chest,the acceleration of children’s head and chest,the moment of neck along Y axis,the stress of neck along Z axis,is the stiffness coefficient of child seat safety belt and the position of the child seat safe belt.Based on the collision of computer simulation to make analysis about safety analysis and safety analysis of performance optimization to the existing domestic products.The result is,first,the stiffness characteristics of seat belts as standard 1,at 0.25 times,the numerical value of the resultant acceleration of children’s head and chest,the moment of along the Y axis is smallest,they are 580,507,17.684 Nm,at 0.5 times the smallest stress of neck along with Z axis is 1836N;second,if the stiffness characteristics of the seat standard 1,at 4 times the numerical value of the resultant acceleration of children’s head and chest,the moment of along the Y axis is smallest,they are548.9,544.3,16.307 Nm,at 0.5 times the smallest stress of neck along with Z axis is 1834N;last,in the position of child seat strap,in the middle position,the numerical value of the resultant acceleration of children’s head and chest,the moment of along the Y axis is smallest,they are 644.9,551.6,17.156 Nm,when it in the bottom,the moment of along the Y axis is smallest is 1920 N.