Identification and validation of constitutive model and fracture criterion for AlMgSi alloy with application to sheet forming

The present work addresses a modelling strategy for computer-aided formability evaluation of sheet metals and sheet metal forming operations using shell element analysis. The mechanical behaviour of the rolled AlMgSi alloy AA6016 in temper T4 is characterized by a series of different tests, including uniaxial tension tests, shear tests, plane-strain tension tests, plane-strain bending tests, bulge tests, square-cup drawing tests, and Nakajima and Marciniak-Kuczynski (M-K) formability tests. In addition, texture-based polycrystal yield surface (PCYS) calculations are carried out for identification of the anisotropic yield surface of the constitutive model. The uniaxial tension tests, shear tests and PCYS calculations are used to identify the material constants of the constitutive equation and failure criterion, while the remaining tests are left for validation. Finite element models of the tests are established and simulations are performed and compared with the experimental data. (C) 2009 Elsevier Ltd. All rights reserved.