| Crashworthiness and lightweight of the car body are hot research areas in the carengineering field which have social and economic significance. It is of greatengineering and practical significance to introduce the forming effect into the crashsimulation and optimization design, and the accuracy of the crash simulatio n andreliability of the optimization design could be increased therefore. Based on meshvariables mapping method, the influence of forming effect on crash performance andcrashworthiness optimization design is studied, and specific research can be describ edas:First of all, the theoretical method which is used to transfer forming effect intocrash simulation, namely mesh variables mapping method based on inverseisoparametric transformation is studied. Mesh variables after forming process areaccurately mapped into the crash simulation model, and theoretical foundation forfront bumper beam crash simulation and crashworthiness optimization is prepared.Secondly, based on mesh variables mapping method, forming effect is introducedinto the low-speed crash simulation model of the front bumper beam. After comparingthe mesh variables between forming and crash models and confirming the accuracy ofmapping process, crash analyses under different conditions are conducted, includingwithout considering forming effect, considering two kinds of forming effect,considering only thickness and considering only equivalent plastic strain. Analysesresults indicate that, forming effect has an significant influence on crash performance,the influence of thickness and equivalent plastic strain on crash performancesomehow offset each other, and the influence of equivalent plastic strain is moresignificant.Finally, The front bumper beam is taken as example to study the influence offorming effect on the crashworthiness optimization design. The forming effect isconsidered in the crash simulation and crashworthiness optimization is conductedbased on accurate crash simulation, then the comparison of crashworthinessoptimization with considering forming effect and without consi dering forming effectis studied. Uniform Latin square design of experiment and response surface methodare used to optimize the section size of the front bumper beam, and the simulation ofthe optimization results is conducted. As a result, compared to the optimization result without considering forming effect, the SEA of the optimization result consideringforming effect is increased to some extent, while the intrusion and impact force arealmost the same.Based on mesh variables mapping method, coupling simulation of forming andcrash is realized, and it is a meaningful guidance to improve the crash simulationprecision. The crashworthiness optimization of the front bumper beam consideringforming effect provides a reference for crashworthiness optimizati on design. |
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