中文摘要：

采用合理的板料形状以及合理地设置拉延筋,能够改善板料在成形中的流动性,从而减少起皱、拉裂等质量缺陷。以某汽车后地板前横梁为例,利用Dynaform坯料尺寸估算模块,对凸模进行逆向展开获得轮廓线,以偏置后的轮廓线的外切矩形确定板料初始形状,并进行成形仿真;在分析成形极限和金属流动方向的基础上,为消除零件的开裂缺陷,对初始板料左、右上角进行切除,获得修正的板料形状。仿真分析结果表明,修正后的板料增加了左、右上角材料的流动性,降低拉深变形的阻力。为减小零件的起皱缺陷,在模具中间部分设置拉延筋,拉延筋的设置降低了中间部分材料的流动性、增加了拉深变形的阻力,使变形趋于平衡,从而提高了零件的成形质量。

英文摘要：

In sheet metal stamping forming process,an appropriate shape of blank and reasonably setting of drawbeads reasonably can improve metal flowing properties and reduce wrinkling and cracking,thus avoid forming defects. For a front beam of rear floor part in the car,its forming process was analyzed by the commercial software Dynaform. The punch surface was unfolded and the contour line was offset by utilizing the BSE（ Billet Size Estimation） module of Dynaform. A forming process of the contour line-offset blank was simulated.On the basis of forming limit diagram and edge movement of the sheet metal,the upper left and right corners of the blank were cut off to avoid cracking defects,and the optimized blank was obtained. The obtained simulation results show that flow of the metal at the upper corners is significantly improved and the drawing resistance is reduced. Moreover,in order to solve the wrinkling problem,drawbeads are set in the middle of contact surface between die and blank holder. The experiment results show drawbeads impair the metal flow in the middle zone of the blank and improve drawing resistance. Therefore,its forming quality is improved.