A novel phenomenological material model and calibration for high temperature material behaviour of AA5083

With the constant prioritization for vehicle lightweighting, high temperature forming processes are increasing in demand due to their capability to produce large and complex parts in a single forming operation. Superplastic forming is utilized to form such parts, but this process typically requires long forming times. To remedy this, an increasing number of processes are being developed which utilize a higher and more variable strain rate history during the forming process. As a result, there is a growing need to develop material models capable of simulating high-temperature forming processes characterized by variable strain rates and different deformation mechanisms acting at different strain rates. This study proposes the utilization of physical based modelling concepts to construct a simple, phenomenological model that is easy to use within industry. Consequently, tensile tests were conducted on aluminum alloy AA5083 at temperatures of 400°C, 450°C and 500°C, at strain rates ranging from 0.0005 s ⁻¹ to 0.15 s ⁻¹ . Additionally, an iterative model parameter calibration procedure is proposed, verified, and validated with LS-DYNA finite element simulations to achieve accurate predictions of material behaviour all the way up to the onset of localized necking. The generated material model(s) yielded validation metrics greater than 96% for the investigated data sets. The accuracy of the model was further assessed using tensile testing data with changing strain rates, yielding validation metrics on average greater than 90%.