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.