Development of an Analytical Model for Calculating the Stress Distribution of a Strip via the Roll Forming Process

Roll forming is a sheet metal forming process and is being increasingly used in the oil industry to mine crude oil. As mining regions experience unfavorable conditions, such as high pressures, corrosion, and cold, the quality of steel pipes needs to be guaranteed by improving the roll forming process. Several analytical models have been developed to determine the stress-strain distribution during forming. By assuming that the cross-section of the strip at each roll stands as a single plane, the strain distribution of the strip during the flower pattern stage was derived to observe the local deformation. Most of them does not consider the strain and stress distributions together or the advanced estimations including cyclic hardening due to loading and unloading process. In this work, a novel analytical model for calculating the strain distribution was integrated with the stress calculation model, which includes a cyclic hardening model. Moreover, the stress-strain results at each roll stand can be shown by developing the post-processing code to show how the internal status of the strip briefly. By using the model, the fact that the stress distribution and yield conditions are different was proven when the flower pattern was different.