Front Bumper Beams Crashworthiness Research With Considering The Impact Of Stamping

With the development of automobile industry,automobile passive safety attained more and more attention.How to improve car crash simulation accuracy is a major difficulty to automotive passive safety research.Bumper beam is typically thin-walled automotive safety parts,which is a critical automotive components to improve passive safety.Most bumper beams obtained through the stamping process,which inevitably lead to the thickness of the beam collision,stress and strain changes occur,which will have a great impact on the impact performance of the body structure.The traditional automobile crash simulation is very general and the forming history of the anti collision beam was rarely studied as an influence factor.Therefore,there is a lot of error between the traditional car crash simulation and real car collision test.In order to simulate the automobile crash simulation accurately.In this paper,the impact crashworthiness of the front bumper beam with considering the forming history is studied.The main contents are as follows:First,In order to prove that the vehicle collision results considering the forming history can more accurately reflect the results of the real vehicle collision,the analysis of the stamping process of a certain type of car in China is analyzed in this paper,and then the grid mapping was carried out.In the end,the impact of the grid map before and after the collision of the vehicle is fitted to the vehicle crash finite element model,the frontal 100% rigid barrier crash simulation was carried out respectively,and the results of the acceleration waveform of the vehicle after the collision are compared with the results of the real vehicle crash test.The vehicle frontal crash simulation results of the grid mapping of the collision beam were compared with that of the vehicle frontal crash simulation results which were not carried out by the grid map.The result was more close to the actual collision results.Secondly,in the paper two kinds of structure forms of collision avoidance beam model were established.According to the requirements of the IIHS regulations and the characteristics of the low speed collision of the bumper system,determine the collision simulation conditions.By cleaning up the geometry model of the bumper system,thedefinition of finite element mesh size,material properties are defined,the establishment of constraints and load conditions,contact and hourglass control,collision bumper system finite element model was established.Third,choose the beam material,thickness,structure as the influence factors,through the orthogonal experiment design,attained experimental scheme of numerical simulation,the collision process of the bumper system was simulated.The factors that affect the impact resistance of the beam were obtained by the simulation results,and the optimal structure of the beam was determined.The parameters of the optimal structure of the beam were designed,and the four variables of the cross section size of the cross section were defined.Using response surface method to establish the mathematical model of variables and maximum energy absorption,minimum mass and minimum displacement.And the particle swarm optimization algorithm is used to find the optimal response surface model,and the optimal contour size of the beam was obtained.Finally,the stamping forming simulation of the structure and the cross section size optimization of the anti collision beam was carried out.Taking into account the forming history of the impact of the crash beam forming results and without taking into account the impact of the history of the impact of the crash beam structure of the collision file for grid mapping.The collision file of the impact beam structure with the history of the stamping process was obtained.Consider the forming history anti-collision beam collision structure file with the anti-collision beam structure files were installed to conventional collision model to carried out the vehicle front 100% rigid wall impact vehicle verification and the front 40% offset variable barrier collision vehicle verification.In this paper,from the aspect of improving the accuracy of the simulation analysis of automobile collision,a collision simulation scheme considering the impact of stamping process was proposed,optimization of the structure and cross section parameters of the front bumper beam,which is significant for the high precision impact analysis and the whole vehicle safety design of the important structural components of automobile.