Numerical investigation on plastic forming for heat transfer tube consisting of both dimples and protrusions

In this paper, a new method and manufacture apparatus for producing enhanced tube with dimples and protrusions (ETDP) have been proposed for the first time. The main objective of the present work is to investigate the mechanical responses of the smooth tube in extruding process. Additionally, the effects of extrusion depth, extrusion spacing, teeth radius, and tube wall thickness on deformation, stress, plastic strain, and extrusion force of ETDP were also investigated. From this investigation, it found that the dimples formed due to the smooth tube protruded, and protrusions formed due to the smooth tube dented. The maximum deformation, stress, and plastic strain at protrusion regions are larger than dimples. Among the investigated different extruding parameters, it found that the stress, deformation, and plastic strain increase with the increasing of D and . However, it increases with the decreases of extrusion P. In addition, R has no obvious effect on mechanical behavior of ETDP at current arrangement. The results can help to understand the forming process parameters and improve the forming quality.