Analysis and Control of Twist Defects of Aluminum Profiles with Large Z-Section in Roll Bending Process

This paper focuses on the twist defects and the control strategy in the process of four-roll bending for aluminum alloy Z-section profiles with large cross-section. A 3D finite element model (3D-FEM) of roll bending process has been developed, on the premise of the curvature radius of the profile, the particularly pronounced twist defects characteristic of 7075-O aluminum alloy Z-section profiles were studied by FE method. The simulation results showed that the effective control of the twist defects of the profile could be realized by adjusting the side roller so that the exit guide roll was higher than the entrance one (the side rolls presented an asymmetric loading mode with respect to the main rolls) and increasing the radius of upper roll. Corresponding experimental tests were carried out to verify the accuracy of the numerical analysis. The experimental results indicated that control strategies based on finite element analysis (FEA) had a significant inhibitory function on twist defects in the actual roll bending process.