Yield Locus Evolution at Non-Proportional Loading in Terms of the Synthetic Theory

This paper addresses a novel approach to the construction of yield surfaces for the case of both proportional and non-proportional loadings, which are studied in the three-dimensional stress deviatoric space. For the mathematical apparatus, the Synthetic theory of irrecoverable deformation is utilized. The following three loading regimes are considered: uniaxial tension, uniaxial tension with subsequent torsion, and uniaxial tension with subsequent torsion in the opposite direction. The model results fit well with the 2024 T4 aluminum alloy experiments. Accounting for minimal computer time and requirements, the theory presented here is a promising method for predicting the deformation state of material subjected to various loading trajectories.