| The development cycle of a new type car mainly lies on its auto panels. It is very difficult to obtain high quality products only with empirical formula and traditional "trial and error method" due to the complex auto panels, rigid manufacturer precision and surface quality of the auto panels and a lot of factors affecting its stamping forming process, in addition, the development cycle is long and its costs is very high. Therefore, the auto panels stamping forming simulation technology has vital significance in cutting down auto manufacturing circle, reducing cost, improving design quality and enhancing market competitive ability.In this paper, taken a medium truck's roof panel for example, some researches in studying its quality problems and solutions during the roof panel's forming process was done by numerical simulation and optimization technology, and the best forming conditions which has reference significance to the actual production was selected out.Based on the basal theory of sheet metal forming, simulation technology and optimization technology was researched in this paper. Firstly, using numerical simulation in drawing forming and trimming process and its spring-back, a medium truck's roof panel was taken into account to obtain the deformation characteristics of the blank and study the quality problems that may appear in the forming process and the impact of the parameters (gap between die and punch, friction modulus, blank holder force and draw-bead resistance); Secondly, this paper set up a multi-objective model between its impact factors and forming quality and obtained corresponding orthogonal samples by finite element method. It also built a non-linear mapping between its impact factors and forming quality by designing a BP neural network in MATLAB software, and then obtained an optimized set of impact factors in the forming process by multi-objective genetic algorithm; Finally, based on the above work, the numerical simulation in flanging process and its spring-back was researched, and the optimized parameter combination was determined by orthogonal experiment and the results was verified at last.The results by contrast show that numerical simulation can forecast the forming defects, and the optimized parameter combination obtained by orthogonal experiment and MATLAB optimization technology is exact. The optimization results can guide the actrol production. The technology course can not only increase the work efficiency greatly and reduce the production costs but also improve the quality of products, the popularization and application of which in this field is worthy. |
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