Computer aided development of a bending–drawing test for thin metallic sheets

Abstract

Abstract The ability of deep drawing or ironing of thin sheets to produce food or beverage cans is associated with the material characteristics such as surface roughness, anisotropy and ductility. Quite different bending test applications have been suggested by several authors, starting from Nine, to estimate friction for sheet metal forming. Brun later on, proposed a bending–drawing test made under higher compression loads, to measure the residual ductility related to inclusion content, supplying the information that the uniaxial tensile test is not able to produce on metallic sheets. FEM models were made for this bending–drawing test using the LS-DYNA3D and ABAQUS explicit codes, to simulate numerically several features concerning the rather complex strain and stress distributions, as: (i) material parameters, (ii) some tooling and specimen dimensions and (iii) process conditions. To develop under realistic conditions the numerical simulation of this drawing–bending test, a very simple experimental tool was made for: (iv) identifying the more relevant parameters and test results and (v) validating the simulation. The forecasted results by the numerical simulations were in quite good agreement with the experimental results concerning the strain distribution after multiples stages and the holding force, but not so much the drawing forces. Starting from this experimental validation, some tooling parameters, specimen dimensions and process conditions have been improved by numerical simulation, the test now being sensible to the plastic anisotropy. The numerical simulation coupled with very simple experimental apparatus has shown to be a very powerful methodology for new test development.