Draw bending of dissymmetric channel section with variable axial tension

Recently, aluminum alloy sections have been used in various areas such as general structures and automotive components. Aluminum channel sections with appropriate shapes for structural rails have the advantages of having a light weight and a high bending rigidity. In these areas, components with a part of a curved configuration are utilized. Therefore, bending process is required to manufacture these components. However, undesirable deformation such as flattening and wrinkling occurs easily when bending thin-walled sections. As a method of preventing undesirable deformation, the use of axial tension and constraining dies is suggested. In a previous study, the effect of constraining dies on undesirable deformation was confirmed in the draw bending of dissymmetric channel sections. However, the approach using the axial tension is necessary to determine the effect of axial tension on the working property of dissymmetric channel sections. Axial tension is effective for flattening and wrinkling on a compression flange by compression stress. The appropriate axial tension was accurately varied with bending angle to prevent undesirable deformation. In this work, the stress analyses of draw bending with axial tension were performed by finite element analysis (FEA). From these analyses, the appropriate axial tensions at bending angles are demonstrated. An experiment on draw bending with variable axial tensions, which was performed by FEA, was carried out. From the results, the effect of appropriate axial tension on the working property of dissymmetric channel sections was confirmed by FEA and experiment.