Multipass roll forming of variable-curvature elliptical panels using the angular function based on UOSDM

Variable-curvature elliptical panels are widely used, however, their forming process is complex. This study investigated the influence of different bending-angle-distribution methods and process parameters on the bending deformation and springback of the panels. The universal optimized springback defect method (UOSDM) is proposed for mitigating springback to improve the forming quality. The results show that the springback angle of the plate increases with the decrease of thickness and yield strength. The maximum stress and plastic strain of the plate manufactured by UOSDM are 268.88 MPa and 0.303, which are smaller than those by other methods. The overall stress distribution is more uniform and defects are not easy to occur. This study intends to reveal the uneven deformation mechanism and precise plastic forming law of curved parts with variable curvature, improve the forming quality of sheet metal and realize the precision manufacturing of complex parts with variable curvature by roll forming.