Cyclic stress-strain behaviour of alloy AA6060, part I: Uniaxial experiments and modelling

An experimental and numerical study of the uniaxial cyclic behaviour of the aluminium alloy AA6060 in tempers T4 and T6 is reported. Material characteristics studied through the experimental programme are the monotonic stress-strain curve, the shape of the hysteresis loops, cyclic hardening and softening, mean stress relaxation and memorization of prior strain histories. A model of cyclic plasticity, proposed in the literature, is used to simulate the physical behaviour of the alloy in temper T4. The model utilizes multi-component forms of kinematic and isotropic hardening variables with non-linear evolutionary rules to describe the hysteresis loops and the transient behaviour of the material. The evolution of the Bauschinger effect and the memory of prior strain histories are properly modelled through additional internal variables. Tests and simulations are compared for temper T4, and good agreement is obtained between physical and correlated behaviour.