Finite element analysis of bending behavior and strain heterogeneity in snake rolling of AA7050 plates using a hyperbolic sine-type constitutive law

Snake rolling is a relatively new asymmetric rolling technique adopting a horizontal roll offset and differential roll speeds. In this study, the deformation behavior in snake rolling of an AA7050 aluminum alloy has been investigated by finite element (FE) simulations using a hyperbolic sine-type constitutive law. The effects of offset distance, thickness reduction, and speed ratio on bending behavior and through-thickness distribution of plastic strains are examined. The optimal speed ratio to obtain flat plates with a negligible curvature is identified for each combination of offset distance and thickness reduction. Examination of the plastic strains in the flat plates indicates that, compared with conventional rolling, snake rolling increases the magnitude and through-thickness homogeneity of the accumulative equivalent strains, and it improves the through-thickness homogeneity of the strain in rolling direction and shear strain at an expense of their magnitudes. Despite the potential significant effect of asymmetric distributions of contact shear stresses on bending behavior, no simple correlations can be identified between the characteristics of cross shear region and the magnitude or direction of bending. Experiments are conducted to validate the prediction of bending behavior by the FE simulations.