Investigating Ovality and Wall-Thinning Behaviors in Free-Form Bending of Thin Pipe Bends with Varying Guider Length and Roller Die Diameter

Abstract This study investigates the influence of guider length and roller die diameter on the ovality and thickness reduction of pipe bends formed using the freeform bending method. Finite element simulation is employed to analyze a three-segment pipe bend. The analysis reveals that the beginning of the third bending segment exhibits the highest ovality, which directly correlates with circumferential strain. Optimal values for roller die diameter and guider length are determined for the given geometry, and a spatial bend design is proposed to minimize the percentage of ovality. The findings provide valuable insights for optimizing the bending process and achieving reduced ovality in pipe bends.