Research On Optimum Design Of Body Structure Against Side Explosion Impact Protection

In order to improve the side explosion protection ability of the vehicle,this paper improved the design of the vehicle side structure according to the responses of the vehicle structure and the injuries of the occupant in the side explosion case,and used the multi-objective optimization design,which not only improved the side explosion protection ability of the vehicle,but also reduced the quality of the improved structure.The main research contents and conclusions are as follows:Firstly,the accuracy of the SPH-FEM joint algorithm was verified by the fixed supported square target test,then the finite element model of the fragment warhead was established,and comparing the fragment velocity calculated by simulation with that calculated by theory,the accuracy of the warhead finite element model was verified.Secondly,the finite element model of the trolley test bench was established,and the lower limb injury and floor deformation of the occupant were analyzed by combining the simulation and test,the results show that they have good consistency,which verifies the accuracy of the finite element model.On this basis,the vehicle side explosion simulation was carried out,the structural responses of the vehicle body,the motion response and the occupant injuries were analyzed,and the main damage parts and the main causes of the occupant injuries were analyzed.The results show that the head,neck and shoulder of the passenger are the main damage parts,and all of these injuries are from the collision with the body side wall.Subsequently,the side wall structure of the vehicle body,including the door,B-pillar and occupant restraint system,were improved.The explosion-proof beam structure and energy absorbing material were added between the inner and outer panels of the door.The material of B-pillar was replaced with high-strength steel and reinforced fasteners were added.The shape of head restraint was changed and the seat connecting rod was added.The results showed that the protection ability of the improved vehicle was improved and the occupant injuries reached below the threshold.Finally,the multi-objective optimization design of the improved side wall structure was carried out,which not only reduces the injury of the occupant and improves the protection ability of the whole vehicle,but also meets the lightweight of the structure.