Material and Damage Characterization of the Elastoplastic Response of the EK4 Deep Drawing Steel

BARRERA; CLAUDIO GARCÍA-HERRERA; CELENTANO, DIEGO; SIGNORELLI, JAVIER W.

Metals

MDPI

Año: 2022 vol. 12 p. 1 - 13

Although EK4 drawing steel is nowadays widely used to manufacture a great variety ofparts, it exhibits a marked normal and planar anisotropy that can make it difficult to control theprocess during its forming. In order to achieve an accurate description of the elastoplastic materialresponse in sheet forming operations, this work presents a detailed material and damage characterizationof EK4 deep drawing steel through a two-step methodology involving both experiments andfinite element simulations. Firstly, tensile tests on sheet samples cut along the rolling, diagonal andtransverse directions were carried out. The corresponding measurements were used to calibrate thematerial parameters related to the following modeling approaches adopted in the present study: theHollomon hardening law, the non-associated Hill-48 phenomenological constitutive model and theanisotropic Hosford-Coulomb ductile fracture criterion. Secondly, this characterization was assessedand validated in the numerical simulation of the technological Erichsen test in which the material ismainly subjected to a biaxial stress state. The obtained predictions show a good agreement whencompared with the corresponding experimental measurements of the punch load?displacement curveand thickness radial profile at the final fracture stage of the sample.