Application of the GTN Model in Ductile Fracture Prediction of 7075-T651 Aluminum Alloy

In this paper the capability of Gurson-Tvergaard-Needleman (GTN) model in the
prediction of ductile damage in 7075-T651 aluminum alloy is investigated. For this
purpose, three types of specimens were tested: Standard tensile bars, Round notched
bar (RNB) specimens and compact tension (C(T)) specimens. Standard tensile bar
tests were used to obtain the mechanical properties of the material and to calibrate
the independent parameters of GTN model. RNB and C(T) specimen test results
were used for validation of the calibrated parameters. Finite element analyses were
carried out using ABAQUS commercial software for two purposes; calibration of
the GTN model parameters and validation of the model predictions. The comparison
between the finite element analyses and the test results suggested that the GTN
model is capable of damage prediction in notched specimens, but not a good in
cracked specimens. Finally, To show the applicability of the model in industry-level
problems, the model is used for damage predictions of internal pressure vessels
made of 7075-t651 aluminum alloy.