Crystal plasticity models are used in conjunction with the Marciniak-Kuczyn
ski approach to predict forming limit diagrams (FLDs) of different annealed
aluminium alloy sheet (AA6xxx series) with various initial crystallographi
c textures. The numerically determined FLDs are compared with experimental
data. Two distinct models are used for FLDs predictions. The first method i
nvolves the calculation of yield surfaces from a rigid-plastic rate insensi
tive crystal plasticity model without recourse to the use of analytical yie
ld functions. In the: second method, the response of the material is based
on an elastic-viscoplastic crystal plasticity model. Both methods take into
account texture evolution during deformation. By taking into consideration
the elastic part of the deformation, the elastic-plastic model can predict
the shift of the forming limit curve minimum towards positive minor strain
s. It is found that the Goss orientation {011}[100] present in the initial
texture as well as the microstructure influence significantly the formabili
ty. (C) 1998 Elsevier Science S.A. All rights reserved.