Numerical study on deformation behaviors of thin-walled tube NC bending with large diameter and small bending radius

With respect to wrinkling, wall thinning and cross section deformation, combined with analytical description, the deformation behaviors of thin-walled tube NC bending with large diameter D/t (50.0-87.0) and small bending radius R-d/D (1.0-2.0) are explored via a series of reliable 3D-FE models under ABAQUS platform. The results show that: (1) The segmentation feature is observed for the deformation fields such as effective compressive/tensile regions tau(c)/tau(t), stress/strain distributions, wrinkling tendency, wail thinning and cross section deformation. With smaller R-d/D, the tangent stress increases and becomes more inhomogenous. The maximum tangent stress sigma(phi) at the intrados increases by 46% with R-d/D from 2.0 to 1.2. While the distributions of sigma(phi) are nearly similar with larger D/t. With smaller R-d/D and larger D/t, the velocity variation of tube materials becomes more obvious. (2) The wrinkling tendency and cross section deformation degree Delta D increase with smaller R-d/D and larger D/t; With smaller R-d/D, both the wall thinning and thickening degrees increase. The maximum wall thinning and thickening degrees increase by 24.0% and 52.5%, respectively. However. with larger D/t, the wall thinning degree increases, while the thickening degree decreases significantly. The maximum wall thinning degree increases by 31.3%, while the maximum thickening one decreases by 58.9%. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.