外径不等杯-杯型复合挤压过程的数值模拟

Numerical Simulation of the Cup cup Axisymmetric Combined Extrusion with Different Outer Diameter

采用刚塑性有限元法对外径不等杯－杯型复合挤压过程进行了数值模拟，并给出网格重新划分技术和处理八节点四边形等参元奇异点的方法。数值模拟结果表明：对于外径不等杯－杯型复合挤压在晚期非稳态流动阶段有压力回升现象；两端变形程度的大小对金属流出量大小起主要作用，摩擦条件的改变对金属流出量大小影响很小。变形力和金属流出长度的计算结果与实验结果相吻合。

In this paper, the rigid plastic finite element method is used to simulate the cup cup combined extrusion with different outer diameter. A new method for handling the singularity in the eight nodes isoparametric quardrilateral mesh is proposed. The numerical simulation results show that the deformation force rises again during the late unsteady flowing period of the cup cup combined extrusion with different outer diameter, and that the material out flowing volume towards the backward and forward exits is mainly determined by the deformation degree of the backward and forward extrusion, and hardly affected by the friction conditions. The deformation force and the ratio of the backward out flowing length and the forward one calculated by the FEM codes agrees well with the experimental results.