Research on sheet metal semicutting process using coupled and uncoupled damage model

Abstract

An axisymmetric finite element model was created using ABAQUS software to study the evolution of the ductile damage in the process of sheet metal semicutting. A modified Gurson–Tvergaard–Needleman (GTN) porous material model and a modified Rice–Tracey ductile fracture model which takes into account the influence of stress triaxiality and deviatoric stress tensor on material damage, were introduced and the improvements of them were verified based on a single element uniaxial tension test and different tensile tests with notched specimens. After that, both of them were used for elastoplastic sheet metal semicutting analysis. By analysing the distributions of hydrostatic stress, equivalent stress, equivalent strain, stress triaxiality and fracture of sheet metal in the process of semicutting parts based on simulation and the corresponding experimental results, some phenomenon related to void nucleation, growth and coalescence in the sheet metal semicutting process was discussed.

Keywords:

• Semicutting
• GTN damage model
• Void nucleation
• Ductile fracture criterion

The authors would like to express their gratitude to the National Science and Technology Major Project of China (no. 2009ZX04004‐091) and National Natural Science Foundation of China (no. 50975175) for the financial support to this study.