engleski

Earing predictions for Al2008-T4 sheet

Generally, sheet metals demonstrate anisotropic plastic behaviour. That means that yield stresses and Lankford coefficients, obtained in the uniaxial tensile testes performed on the sheet specimens with the different alignment to the rolling direction, demonstrate orientational dependence. Also, available experimental data for the selected aluminium alloy sheet Al2008-T4 demonstrate yielding asymmetry. That means that there is difference between yield stresses in tension and compression. In this article, a constitutive plasticity model that enables description of the yielding anisotropy and the yielding asymmetry is presented. The model is tested in predicting the cylindrical cup deep drawing process for the considered aluminium alloy sheet. In the cylindrical cup deep drawing, due to material anisotropy, cups with unequal heights are produced. This undesired effect, known as earing, requires additional manufacturing operations and causes material loss. By modifications of the initial blank shape, earing can be reduced and production costs minimized. In finding the optimal blank shape, numerical simulations can be used as the valuable tool, but reliable material model is required. The presented study demonstrates that the presented constitutive model results in acceptable predictions of the cup heights for the considered aluminium alloy sheet.

cup drawing ; earing ; yielding asymmetry ; non-associated flow rule

U publikaciji je rad prikazan na engleskom i talijanskom jeziku.