Simulation Research On Vehicle Side Impact And Its Structure Optimization

There are several forms of car collision,among them there are three common forms: frontal collision,side collision,and rear-end collision.The incidence of frontal collision has the highest rate,and the fatal injury rate of the side collision is the highest,with the introduction of the national collision regulations and the impact of C-NCAP on consumers is increasing,automakers pay more and more attention to passive safety.This paper is based on the explicit finite element theory in the HYPERMESH software environment to carry out the vehicle side impact simulation analysis and the optimization design of the key components of the side wall structure,in order to improve the anti-collision performance of the side structure of the vehicle.Firstly,the existing vehicle finite element model is modified in the HYPERMESH software environment,and the movable deformation barrier(MDB)model is set up.The contact setting of the collision between the whole vehicle and the MDB model is set and submitted.LS-DYNA performs the operation.The reliability of the model is evaluated by the calculated energy change curve,mass change curve and intrusion curve,and the direction that the model needs to be improved is proposed.The first is to improve the B-pillar,since the simulation of the side collision simulation of the whole vehicle is carried out by the computer for a long time,in order to save time,the B-pillar is more efficiently optimized,and the simplified model is extracted for the B-pillar,which simplifies the model and the vehicle model is compared to prove the reliability of the simplified model.The simplified model is used to design the B-pillar for the tailor-welded plate.The plates of different thicknesses of different materials are welded together to form the B-pillar,and the position of the laser-welded wire of the B-pillar is considered.The B-pillar is found by the intrusion of the B-pillar.The optimal solution in the optimization,the optimal solution is brought into the vehicle,and the optimization effect is obvious but still lacking.Further consideration is given to changing the cross-sectional shape of the door anti-collision beam for the B-pillar material(CR450/980 TR and CR480/ 1180TR),B-pillar thickness(1.2mm and 1.4mm),door anti-collision beam structure(O-section and W-section)constitute a three-factor two-level orthogonal test.The optimization method adopts the multi-factor weight optimization method.Through the intrusion amount and intrusion speed index of key nodes,the optimal scheme is obtained for various schemes in the orthogonal experiment.The optimal scheme is compared with the original scheme,and the comparison is verified by analysis and comparison.The optimization scheme has greatly improved the side collision performance of the original vehicle.The orthogonal test results show that the material thickness matching of each position of the B-pillar can improve the side anti-collision performance of the vehicle,including the selection of the vehicle door anti-collision beam,which also has an impact on the side crashworthiness of the vehicle.The utilization can reduce the intrusion and intrusion speed of the key nodes on the side of the vehicle.The research carried out in this paper provides a technical support for the improvement of the side crashworthiness of the car and the safety of the occupants in the car.