Numerical analysis of cold roll forming of symmetrical open sections

A general procedure for numerical analysis of cold roll forming for production of symmetrical open sections is presented. In this procedure three-dimensional geometry of the middle layer of the strip is assumed and also in the first deformation region, a variable width is proposed. Then three-dimensional coordinates of any point of the strip are determined and longitudinal, transversal and shear strain components are calculated. Assuming an elastic-linear work hardening material, stresses in the same directions are obtained. The Bauschinger effect is also taken into account. Deformation energy is calculated and the pre-estimated geometry is modified by minimization of deformation energy. It is shown that predicted strains and three-dimensional geometry are consistent with experimental data. Stress distributions are presented. Consideration of shear stresses and also the Bauschinger effect are among the new concepts of this paper.