Optimization Of Automobile Safety Performance Based On Hip Injury Of Occupants In Side Impact

Traffic accidents occur frequently in China.How to reduce driver and occupants injuries in traffic accidents has always been the focus of vehicle safety research.In vehicle side impact,the impact on the hip has characteristics of wide range and high strength,which is likely to cause disability to the driver and occupants.Therefore,in-depth study of the injury of the occupant hip in side impact is of great significance to improve the passive safety of vehicles.The modeling method of human biomechanics finite element model is studied in this thesis.Based on the biomechanical model of human lower limb,the hip injury during side impact is analyzed.And based on hip injury,the side crashworthiness of the vehicle is optimized.The main contents of this thesis are as follows:(1)The structure and damage mechanism of human hip are studied.The anatomical structure of human hip is studied.The causes and types of hip injury are analyzed to obtain the injury mechanism of the occupant hip.And the evaluation criteria of hip injury under side impact under different side impact regulations are studied.(2)Establishment and verification of biomechanical model of lower limbs and vehicle side impact are carried out.According to the CT data of the driver’s lower limbs,a biomechanical model of the hip and lower limbs with fine anatomical structure is established,which consists of bone and soft tissue.The biomechanical experiment of corpse is restored by simulation,and the results of simulation and cadaveric experiment are compared to verify the accuracy of the model.At the same time,the tolerance limit of the biomechanical model is studied.According to the crash regulations,the vehicle side impact model is established,and the accuracy of the vehicle side impact model is verified by comparing the deformation and acceleration in real vehicle crash experiment.(3)Side impact safety analysis is carried out.A relatively complete real human body finite element model composed of lower limb model and upper body model is used to simulate the side impact,the results differences between the simulation and the World SID dummy side impact simulation are analyzed.The hip injury is analyzed by the lateral impact volume and bone stress.According to the hip stress,absorbed internal energy and overall acceleration performance,the occupant injury level can reach AIS3+.(4)Vehicle side crashworthiness optimization research is conducted.The materials with higher strength are selected to replace the original structural materials.And the test design of the main structural parts that affect the side impact is carried out,as well as the approximation model is constructed.Based on optimization algorithm,the passenger compartment side crashworthiness are optimized.After determining the optimization scheme,the vehicle simulation is carried out to verify the optimization results.The optimization results show that the crashworthiness of the vehicle side wall is improved,and the total mass of the side wall structure is reduced.