Constitutive relations and fatigue life prediction for anisotropic A1-6061-T6 rods under biaxial proportional loadings

Cyclic stress-strain curves (CSSCs) and fatigue lives were obtained from fully reversed fatigue tests in strain control on two anisotropic Al-6061-T6 rods. The experiments were conducted at room temperature under three types of loading conditions: tension-compression, torsion and combined proportional tension-torsion. Yield loci and flow behaviour were determined and compared with the theoretical predictions. Two anisotropic effective-stress--effective-strain criteria were evaluated.