球形件反复拉深成形工艺有限元模拟及试验

提出了球形件反复拉深成形工艺，对该工艺进行了有限元模拟与试验验证。与一次拉深成形工艺进行了对比分析，结果表明：凹模圆角区与法兰区应力状态及大小基本相同，但在球底区，反复拉深时径向应力和周向应力都远小于一次拉深的应力，球底区径向应力和周向应力基本为压应力或很小的拉应力；反复拉深时球底区厚度方向应变明显减小，一次拉深、二次反复拉深、三次反复拉深成形的制品最薄点减薄率分别为0.189、0.122、0.049，三次反复拉深可实现近等壁厚制品的拉深成形。该工艺与筒底冷校形工艺相结合，可实现近等壁厚深筒形零件的拉深成形。

Finite Element Simulation and Experiments for Repetitive Deep Drawing of Spherical Parts

A new repetitive deep drawing forming of spherical parts was presented and finite element simulation and experiments were carried out. The stress state and values were almost equal in the flange area and in the circle-corners compared with once deep drawing forming, but in the ball bottom area the radial stresses and circumferential stresses were pressure stresses or small tensile stresses, which were much less than that in once deep drawing. The thinning strain of parts is reduced evidently in the ball bottom area for repetitive deep drawing. The thinning rate of forming parts in thinnest point for once deep drawing, 2-time deep drawing and 3-time deep drawing are as 0.189, 0.122, 0.049 respectively.The thinning strain is very small in the 3-time repetitive deep drawing, which realizes near equal-thickness wall forming. Combined with the bottom cold sizing technology, the technology can realize the forming of deep cup with uniform thickness.