Mechanical behavior of 6101 Aluminum alloy

Resumo

The paper aims to study the elastoplastic behavior of the aluminum alloy 6101 in different stress
states. In order to obtain different levels of stress triaxiality and normalized third invariant, six types of test
specimens were carried out: cylindrical, cylindrical with 6 mm and 10 mm notch radius, machined for
tensile test, rectangular specimen for pure shear testing, and two rectangular models for combined loading
test (tension and shear). The experimental data are evaluated and used for the calibration procedure of the
numerical simulations, which are performed in a context where it is assumed that the model based on the
von Mises yield criterion with nonlinear isotropic hardening describes the mechanical behavior of the
material. The experimentally obtained reaction curves are compared for the observed and calculated data,
and it is possible to evaluate the influence of the stress triaxiality, the normalized third invariant and the
calibration point, in the level of plastic strain in the fracture and in the proximity of the experimental result
with the numerical one. For the cylindrical specimens, the increase of the stress triaxiality results in the
discordance between the experimentally observed result and the numerical simulation performed, so that
model does not represent satisfactorily the experimentally observed, for these conditions, must being
request another calibration for model suitability. For the rectangular specimens, the observed result was
that both the stress triaxiality and the third invariant contribute to a distance between the results obtained
experimentally with the experimental results. At the end of the work, the equivalent plastic strain in the
fracture is analyzed as an indicator so that the correct beginning of the fracture can be observed.