On the basis of the rigid viscoplastic FEM theory, a surface defect prediction method for the plastic forming process by FEM numerical simulation has been thoroughly studied. 摘要基于刚粘塑性有限元基本理论，本文深入地研讨了通过有限元数值模拟来预测塑性成形问题中一类表面缺陷生成的方法。
The inner diameter of open die mandrelless extruded tube parts is predicted with the transient rigid plastic FEM.The prediction shows good accordance with experiments. 本文采用非稳态塑性有限元对开式挤压无芯棒缩管稳态成形内径尺寸进行了数值模拟预测，预测结果与实验相符。
