超塑约束胀形贴模过程及厚度分布的FEM模拟

FEM Simulation for the Thickness Distribution and the Attaching-die Process of Superplastic Constrained Bulging

采用大变形刚粘塑性有限元法．成功地模拟了圆板料向轴对称锥形凹模内超塑约束胀形时，胀形件贴模过程。提出了简便摩擦处理方法．给出了保证计算过程稳定性的处理方法。

The constrained bulging techniqtle of superplastic materials into a die is an interesting task on the present superplastic forming theoretical study,and is of important application value in practical forming process.Becauce of the existence of the die,whenever the bulged sheet attaches on die-wall,the change of boundary conditions will often cause numerical instability of finite element simulation. In the present paper,a rigid visco-plastic finite element method with large deformation is successfully applied to simulating the attaching-die process and patterns of stlperplastic constrained bulging of circular sheet toward the interface of axisymmetrical cone-shape die.In the simulation,simple friction treating scheme and stability algorithm are given.