Experimental and Analytical Study of Cold Bending Process for Pipelines

Abstract

The behavior during the cold bending of pipelines was experimentally and analytically investigated. Full-scale cold bending experiments were performed on API X60 and X80 grade line pipes. Finite element (FE) analyses simulated the cold bending process by considering the contact interactions between a pipe and the components of the bending machine. The results of the simulation were in good agreement with the full-scale experiments. The stress-strain relationship and yield to tensile ratio (Y/T) had no obvious effect on the strain distribution after cold bending. The tensile tests quantitatively evaluated the decrease in the yield stress along the longitudinal direction on the cold bends due to the Bauschinger effect.