Application of the theory of representation to describe yielding of anisotropic aluminum alloys

In this paper a rigorous method to extend any isotropic yield criterion such as to describe any type of material symmetry is developed. Using this approach, extensions of Drucker's [J. Appl. Mech. 16 (1949) 349] isotropic yield criterion to transverse isotropy, cubic symmetries, and orthotropy are presented. Comparison with representative sets of data show that the present theory can successfully describe anisotropy of both the plastic strain ratio and yield of aluminum thin sheets as well as the yield anisotropy of extruded bars. (C) 2003 Elsevier Science Ltd. All rights reserved.