Experimental characterization and modeling of aluminum alloy AA3103 for complex single and double strain-path changes

The stress-strain behavior of the aluminum alloy AA3103 subjected to single and double strain-path changes (SPCs) is studied experimentally. The experimental program includes compression-tension, tension-tension, rolling-tension and tension-rolling-tension tests. The considered AA3103 plate exhibits plastic anisotropy, a strong Bauschinger effect with hardening stagnation after strain reversal, cross-hardening and permanent softening after orthogonal SPCs in the tension-tension tests. However, when instead the orthogonal SPCs are obtained by rolling-tension-tests, cross-softening is observed. The same behavior is seen in more complex tension-rolling tension tests. Three state-of-the-art advanced plasticity models are used in an attempt to model the experimentally observed behavior. These models all account for plastic anisotropy and transient effects after SPCs, using a microstructure deviator tensor to describe a fading memory of the deformation history. While the models successfully describe the behavior after strain reversals, they fail to represent the behavior after orthogonal SPCs. It is concluded that the Schmitt angle, on which the current models depend, is not sufficient for a fundamental description of SPCs for the considered AA3103 alloy.