Improvement of springback prediction accuracy for Z-section profiles in four-roll bending process considering neutral layer shift

Aluminum alloy profiles are widely used as major structural components in the aerospace industry. Owing to the diverse section structures and dimensions required, roll bending for profiles with specified cross-sections has become an attractive manufacturing technology. In the present work an expanded study is carried out for springback prediction of profiles in four-roll bending process. An improved theoretical prediction model considering neutral layer shift is developed, with the aim of improving the prediction accuracy for springback of Z-section profiles. The proposed model considers the material properties, geometric characteristics and forming radii. The springback displacements of Z-section profiles for 7075-O and 7475-O aluminum alloy with different thicknesses are predicted using the model. The maximum springback prediction error of the proposed model compared with experimental results is 3.764 %, which is less than the prediction error of the empirical model (11.626 %). The springback prediction for Z-section profiles considering neutral layer shift thus provides a significant improvement in accuracy.