A Yield Surface for HCP Materials Undergoing a Wide Range of Loading Conditions

A continuum yield surface model is developed to describe the evolving anisotropic response of polycrystalline HCP metals over a wide range of strains, strain rates, and temperatures. The model is intended for large-scale parallel finite element codes for both implicit quasistatic and explicit dynamic simulations. Although the yield function is sufficiently general to capture the range of behaviors exhibited by a variety of HCP materials, the parameterization and evaluation is conducted primarily on Magnesium alloy AZ31. The model exhibits sufficient flexibility to capture the anisotropic response of AZ31 under various loading conditions with lower computational cost and complexity than high rate single crystal models. Consequently, it is foreseeable that by fitting the function to high rate polycrystal plasticity results, it may be used as an intermediary to extend crystal mechanics to engineering-scale applications.