Advanced calibration of yield Locus: Integrating stack compression and shear testing techniques

The accurate calibration of anisotropic yield functions depends on the experimental data generated at diverse stress states. Typically, the calibration experiments for plane-stress anisotropic models involve uniaxial tensile tests in three major orientations with respect to the rolling direction (RD) of the sheet and an equibiaxial tension test, the latter requiring specialized testing apparatus. In this work, the anisotropic plastic behaviour of an aerospace grade AA2024-T3 sheet is investigated using a combination of advanced experimental and analytical techniques. The study presents an expanded approach for yield locus calibration, integrating stack compression and shear testing techniques while requiring only a universal testing machine. By combining these complementary experimental approaches, critical data are obtained at a wide range of stress states, including equal biaxial tension and shear-dominated regimes. In addition, plane-strain tension tests are conducted along RD, 45 degrees to RD, and transverse direction (TD) to provide a more comprehensive assessment of the material’s yield locus. By imposing these critical constraints along diverse stress states, the widely adopted Yld2000-2D anisotropic yield function is calibrated based on an associated flow rule.