Investigation on stress and strain distributions of hollow-part with triangular cross-section by spinning

Abstract

The non-circular cross-section hollow-part spinning is one of the recent breakthroughs of the traditional spinning processes. To reveal the mechanism of the non-circular spinning, the spinning process of the hollow-part with triangular cross-section was investigated. The spun part was divided into the straight-side and filleted-corner along the circumferential direction, and the bottom-corner, side-wall and opening-end along the generatrix direction. The simulation results show that during the non-circular part spinning, wrinkling occurs easily at the flange area of the straight-side; the distributions of equivalent stress and strain are 120° uniformly distributed along the circumferential direction. The differences on distributions of equivalent stress and strain between straight-side and filleted-corner are obvious. The maximum equivalent stress locates at the opening-end, where springback occurs easily. The maximum equivalent strain locates at the bottom-corner of straight-side and the centre of the side-wall of filleted-corner, where over-thinning of wall thickness occurs easily. The strain states of the straight-side and filleted-corner are different, the former is approximately in the state of plane strain and the latter is in the state of volumetric strain. A non-circular spinning device was designed and manufactured, a set of experiments were carried out. The experiment results conform well with the simulation one.