Finite Element Analysis of Roll Forming using Roll Flowers with Different Bending Shapes

Roll forming is a manufacturing process that involves plastic forming via bending using a rolling motion. During roll forming, a coil or blank is formed incrementally in a stepless and continuous process with the aid of rolls to fabricate profile rails. The shape of the rolls predicted the incremental deformation in the cross-sections of the U-profile rails. The design of roll forming processes has been investigated to address typical plastic defects, such as roll load and equivalent stress. Roll flower diagrams were designed in the initial stage of the design of the roll forming processes. These diagrams show the cross-sectional shapes of the product at various stages of the process, superimposed on each other. The diagrams contain information for the process design, including the incremental deformation, number of passes, and setup angle of the rolls. These were developed based on the designer’s experience with the material properties and multiple shapes. In this study, roll flower diagrams were designed using the developed formula, considering constant radius-of-curvature or length of curvature zones in the cross-sections of U-profile rails. Roll forming processes were simulated using the commercial FEM code Abaqus to measure the loads of the rolls and equivalent stress history. Simulation and experimental results regarding the shapes of the U-profile rails were compared to validate the process design method.