Indexed by:期刊论文

Date of Publication:2018-07-01

Journal:INTERNATIONAL JOURNAL OF MATERIAL FORMING

Included Journals:SCIE、Scopus

Volume:11

Issue:4

Page Number:527-539

ISSN No.:1960-6206

Key Words:GTN damage model; Shear modification; Stress triaxiality; Sheet metal forming; Numerical simulation

Abstract:Gurson-type models have been widely used to predict failure during sheet metal forming process. However, a significant limitation of the original GTN model is that it is unable to capture fracture under relatively low stress triaxiality. This paper focused on the fracture prediction under this circumstance, which means shear-dominated stress state. Recently, a phenomenological modification to the Gurson model that incorporates damage accumulation under shearing has been proposed by Nahshon and Hutchinson. We further calibrated new parameters based on this model in 22MnB5 tensile process and developed the corresponding numerical implementation method. Lower stress triaxiality were realized by new-designed specimens. Subsequently, the related shear parameters were calibrated by means of reverse finite element method and the influences of new introduced parameters were also discussed. Finally, this shear modified model was utilized to model the small punch test (SPT) on 22MnB5 high strength steel. It is shown that the shear modification of GTN model is able to predict failure of sheet metal forming under wide range of stress state.