Establishment and verification of anisotropic ductile fracture criteria applicable to AA6016-T4 incremental forming

Abstract

In this study, modified GTN and DF2015 fracture criteria considering sheet anisotropy were established by uniaxial and cruciform tests with digital image correlation (DIC) system. Based on Nakazima and incremental forming tests, forming limit curves (FLCs) of AA6016-T4 were constructed, and the effectiveness of the modified ductile fracture criteria was verified. The results demonstrate that both the modified GTN and DF2015 criteria could accurately capture the sheet fracture behavior in the Nakazima tests. While for incremental forming, the modified DF2015 criterion significantly underestimates the sheet forming limit, and the modified GTN criterion presents a good prediction accuracy with experimental results.