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 τ_c / τ_t, stress/strain distributions, wrinkling tendency, wall thinning and cross section deformation. With smaller R_d/D, the tangent stress increases and becomes more inhomogenous. The maximum tangent stress σ_φ at the intrados increases by 46% with R_d/D from 2.0 to 1.2. While the distributions of σ_φ 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 Δ 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