In this paper, the fracture behavior of 2024-T351 aluminum alloy as a key engineering material in the aeronautical industry is investigated under various planar and nonplanar mixed-mode loading conditions involving pure mode-I and pure mode-III loadings. A newly suggested loading setup accompanied by compact tension shearing and tearing (CTST) specimens is utilized to perform fracture tests. Three-dimensional finite element modeling using the interaction integral method is carried out to derive the stress intensity factors (SIFs) and their ratios through the crack front for several mixed-mode configurations. The numerical results reveal that the coupled effect of modes II and III under mixed-mode I/II, I/III and I/II/III loading conditions is remarkable. Moreover, the amounts of SIFs at the center of the specimens are employed to predict the critical fracture loads according to different mixed-mode criteria. Also, scanning electron microscope (SEM) images of the fracture surfaces of CTST specimens are examined to evaluate the effect of different loading angles from a morphological viewpoint. A good consistency can be found among the results of the theoretical solutions of the criteria and the experimental observations for different loading conditions.

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