Simulation of Cold Roll Forming of Steel Panels

This project uses LS-DYNA to simulate the rolling deformation of a flat steel sheet into a panel of particular shape. The process involves the gradual deformation of the steel sheet by passing it through a series of rollers at a constant speed. Each of these sets of rollers is oriented at a slightly different angle to incrementally increase the deformation of the sheet until the desired geometry is obtained in the panel. Since the sheet could be going through several different sets of rollers at the same time, the deformation process is very complex and highly non-linear. During this process, the sheet metal panel undergoes plastic deformation and develops residual stresses. Some of the problems encountered with these panels include localized buckling, undesirable local deformation at the front (head) of the panel and excessive spring back of the end of the panel (tail). These problems are also observed in the results from the simulation and methods to minimize their effect are investigated. Other issues encountered in the simulation include the contact mechanism between the moving panel and a moving roller, effect of roller size and placement, panel thickness, panel speed and roller friction. An adaptive mesh was used to efficiently mesh the plate and rollers at critical locations. The results obtained should help improve both the simulation process and the actual cold-roll-forming-process especially when new or different metals are being introduced.