中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 12 No. 5 October 2002 |
(National Die and Mould CAD Engineering Research Center,
Shanghai Jiaotong University,Shanghai 200030, China)
Abstract:In order to continuously analyze the whole fine-blanking process, from the beginning of the operation up to the total rupture of the sheet-metal, without computational divergence, a 3-D rigid visco-plastic finite-element method based on Gurson void model was developed. The void volume fraction was introduced into the finite element method to document the ductile fracture of the sheet-metal. A formulation of variation of the rigid visco-plastic material was presented according to the virtual work theory in which both the effects of equivalent stress and hydrostatic pressure in the deformation process were considered. The crack initiation of the sheet was predicted and the crack propagation was geometrically fulfilled in the simulation by separating the nodes according to the stress state. Furthermore, the influences of different state-variables on the deformation process were also studied.
Key words: fine-blanking; ductile fracture; finite element method; Gurson plastic potential