Research On The Effect Of Impact Simulation With The Simplified Vehicle Finite Element Model

In recent years,finite element simulation technology has been used more and more widely in the study of vehicle crash safety performance.However,the large number of meshes in the finite element models of automobiles makes the simulation calculation time very long,especially when the human body finite element model is added,the simulation calculation time is further exacerbated.So how to simplify the finite element model of automobile on the premise of ensuring the accuracy of simulation results,study the influence degree of the model simplified to different degrees on the simulation analysis of collision,get the optimal simplified finite element model of automobile,add human finite element model to the simulation of collision,and further reduce the simulation of collision.It is necessary to calculate the time and provide theoretical basis for vehicle collision safety research.This paper gives a comprehensive description of several simplified model methods currently being studied at home and abroad,expounds the advantages and disadvantages of each simplified model method,and chooses one of the simplified methods to carry out follow-up analysis and Research on the simplification of vehicle model.The vehicle model adopted in this paper is a car model established by the National Highway Traffic Safety Administration(NHTSA).The 100%frontal impact model and 40%offset impact model are established to complete the simulation calculation.The validity of the model is verified by comparing with the actual vehicle test results,and it is used as the basic model of the simplified model.In this paper,three simplified models of 100%frontal collision,40%offset collision and side collision are simplified by the method of substructure simplified model.Four simplified models of 100%frontal collision,three simplified models of 40%offset collision and two simplified models of side collision are obtained respectively.The simplified models of 100%frontal and side collisions are set at 50km/h,and the simplified models of 40%offset collisions are set at 64km/h,which have the same simulation conditions as the whole vehicle model.The results show that,by comparing the simulation results of the whole vehicle model with those of the simplified model,the simplification of the vehicle characteristics under three conditions,i.e.energy output,B-pillar bottom velocity and acceleration,front panel displacement,body deformation and door spacing,can best reflect 100%frontal collision,40%offset collision and side collision Model.The simulation time of 100%frontal collision and 40%offset collision simplified model is about 1/2 of the simulation time of vehicle model,and that of side collision simplified model is about 1/3 of the simulation time of vehicle model.Finally,the simplified model is used to improve the body structure and materials of side impact,The effectiveness of the improved method is verified by comparing the results before and after the improvement.which improves the safety of side impact to a certain extent,and provides some reference and help for the improvement of body structure.