A Study On Crash Simulation Considering Forming Influence And Its Application In Security Design

Through detailed cultural heritage sorting and reading, the related domestic andinternational research present condition was summarized. The forming and crash FEMof automotive structural parts was explained and discussed. The influence of forminghistory on crash simulation was explained on theory. The key technology of “precise”crash simulation was researched. The message mapping method was accounted indetailTaking hat rail assembly for example, the influence of forming history on crashsimulation was studied based on rational theoretical model. The specific process ofthese methods is: the forming process of hat rail was finished firstly, and than thethickness variation, effective plastic strain, elongation percentage changing was bringinto the crash simulation model. At last, deformation mechanisms, energy absorptionand shock force was studied through crash simulation. The results show:1) There isbig differences between traditional crash simulation and precise crash simulationconsidering forming history.2) Different forming history will lead to different impactresponses.3) Effective plastic strain increases the stiffness of the beam sections,however, thickness non-uniformity will weaken the stiffness.Based on the NSGA-Ⅱmulti-objective genetic algorithm and Response surfacemethodology, the forming history is utilized in crash process through the optimizationof process parameter(blank holder force and lubrication coefficient). A front railstructure of car was researched used this method. The best crashworthiness andformability was taken as goal function. The result is: the crashworthiness andformability of front rail structure is improved.