An analytical model of roll bending steel pipe formed by three rollers

This study proposes an analytical model to predict the final radius of a pipe manufactured using three-roller bending. This model accounts for various parameters such as the strength of the steel sheet, the thickness of the sheet, the sizes of the rollers, and the distance between the bottom rollers. It has been derived in order to calculate the loading stress distribution and residual stress across the thickness of the plate. Equations to estimate the final diameter of the pipe are developed based on calculations of the loading and unloading moments about the neutral axis. The position of the neutral plane is assumed to be identical before and after the plate is bent. The results of the proposed analytical model are compared with those of the numerical analysis to validate it under various conditions. It is observed that the analytical model estimates the final radius to be approximately 15% greater than the numerical analysis.