Orthotropic yield criterion for hexagonal closed packed metals

In this paper, a macroscopic orthotropic yield criterion, which can describe both the anisotropy of a material and the yielding asymmetry between tension and compression, is introduced. The yield function is expressed in terms of the principal values of the stress deviator, ensuring insensitivity to the hydrostatic pressure. Application of the proposed criterion to magnesium and titanium alloy sheets shows that this model can capture very well the complex behavior of these materials.