| Abstract Scope |
Incremental spin and flow forming are promising manufacturing methods for aerospace Al alloys, though computational modeling of the deformation process is still in the developmental phase. The selection of a constitutive law, within existing finite element models, to describe the underlying material behavior affects prediction of final residual stresses, plastic strains, and part geometries. The large thermal gradients, varied strain rates, and oscillating loading characteristic of spin and flow forming require a constitutive law that accounts for thermal profile, deformation history, and work hardening behavior. This study evaluated the modified Hollomon, Johnson-Cook, and Kocks-Mecking constitutive models for accuracy and predictive capability for AA6061 in the O temper condition. Rolling mill and spin forming experiments were employed for model validation and calibration by monitoring plastic strain through hardness measurements and part geometry scanning. The results suggest that the Kocks-Mecking constitutive model, with inherent path-dependency, most accurately captures the progressive mechanical response. |