Computerized analysis of parameters affecting shape and thickness in cold rolling of strip for soft materials

A conventional 4-Hi cold rolling mill configuration was modelled and a computer program was developed to analyze the effects of inlet thickness, width, desired exit thickness, symmetric and asymmetric jack forces, screw positions, tensions on the strip, roll geometries, and material properties on strip shape and thickness. For the analysis, the finite difference method was used as the discretization technique. The roll force was obtained by integrating the calculated roll-pressure over the are of contact, and elastic distortion of rolls due to the strip interaction was also considered, For determining inter-roll force, the compatibility equation between work and backup rolls was expressed in terms of work and backup roll axis deflection and work roll surface deformation. The second compatibility equation between work roll and strip was expressed in terms of work roll axis deflections, work roll surface deformation, and estimated strip thickness. The calculated thickness distribution was used for determining shape.