Forming characteristics analysis of the cross-section of axially inner grooved copper tube

The simulation of the cross-section forming of axially inner grooved copper tube (AIGCT) is conducted using finite element (FE) software MSC.Marc. The stress–strain distribution, metal flow rule, and contact force are analyzed based on the simulation and experimental results. The results show that gaps in the groove walls are caused not only by the diametric clearance between the inner wall of the copper tube and the mandrel but also the bending deformation of the copper tube. The cross-sectional geometry and surface characteristics of grooves are determined by the multi-tooth mandrel. Smooth transition of the mandrel teeth addendum improves the metal flow and makes contact force vary slightly, which is good for preventing mandrel from failure. Improving the mandrel surface finish can also improve the inner surface quality of AIGCT. The results help to optimize the forming process parameters and improve the forming quality.