The edge wave defect of C-shaped steel during roll forming is a major technical problem. This study aims to elucidate the mechanisms and influencing factors contributing to edge wave defects in C-shaped steel through experimental investigations and numerical simulations, while also proposing potential solutions. Tensile tests were conducted on S550GD to ascertain material parameters, and a finite element model was developed using Marc to simulate the roll bending process of C-shaped steel. This model facilitates the analysis of various factors, including web length, flange length, frame spacing, forming speed, sheet thickness, and bending angle, and the number of forming passes, on the occurrence of edge wave defects in C-shaped steel. A novel method for controlling these defects is introduced. The findings indicate that the edge wave defect arises from an uneven distribution of longitudinal stress in the width direction. In comparison to the original method, the new approach reduces the peak value of longitudinal stress associated with edge wave defects by 64.52% and the fluctuation of longitudinal stress by 45.99%. The optimization of the uneven longitudinal stress distribution resulted in the elimination of edge wave defects. This study offers a theoretical framework for addressing edge wave defects in C-shaped steel.
Liu et al. (Sun,) studied this question.