反向压力对板材粘性介质压力胀形的影响研究

为研究带有反向压力粘性介质压力胀形过程中接触条件对板材成形性的影响规律,利用DEFORMTM-2D结合韧性断裂准则对覆层板粘性介质压力胀形过程进行有限元分析.结果表明:接触表面无摩擦单纯依靠反向压力能够提高板材成形极限,随着接触表面摩擦系数增大,板材壁厚分布愈均匀,板材的破裂位置由试件顶端转移到凹模圆角处,板材成形极限显著提高.因此,在三维应力状态下有效控制板材所受法向压力和界面摩擦力可以提高板材成形性.

Effect of backpressure on the formability of sheet metal during viscous pressure bulging

To investigate the effect of normal pressure and contact friction on the formability of sheet metal,the viscous pressure bulging tests of overlapping sheet metals were presented and then simulated by the finite element code DEFORM-2D combined with the ductile fracture criterion. The results show that the forming limit of the sheet metal can be improved by normal pressure simply;the distribution of thickness turns to be more uniform with the interface friction coefficient increased,and the fracture locus tra...