Application of Non-Uniform Stretch Flanging Theory to Edge-Crack-Prevention Product Design

International Deep Drawing Research Group 37th Annual Conference

Tabata, R.^1 ; Nitta, J.^1 ; Yonemura, S.^1 ; Mizumura, M.^1 ; Hiwatashi, S.^1

Nippon Steel and Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu, Chiba

293-8511, Japan^1

关键词: Circumferential strain;    Corner radius;    Edge cracks;    Edge fracture;    Flange height;    Flat-top;    Non-uniform;    Strain distributions;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/418/1/012046/pdf
DOI  :  10.1088/1757-899X/418/1/012046

来源: IOP

【 摘 要 】

In order to quickly obtain an appropriate (semi-)product shape that prevents edge fracture in stretch flanging, the non-uniform stretch flanging theory proposed by Nagai was applied to the prediction of strain distribution observed in sheet metal forming of a product with a flat top and a concave wall. The strains calculated by the finite difference method along the flange edge are comparable to those obtained by finite element analysis. Furthermore, flange height h, corner radius R, and shape angle θ were selected as significant factors on circumferential strain c along the flange edge. The investigation on the effect of those factors shows that c increases as R decreases, h increases, and as θ increases. A further increase in θ, however, reduces the increasing rate of c .