Özet:

Additive manufacturing (AM) using 3D printing techniques is widely used not only in prototyping, but also in production of structural elements in many applications such as medical science and biomechanical engineering. Therefore, it is highly important to investigate the fracture mechanics of components and engineering materials made with 3D printing techniques with the aim of application in biomechanical components. In this study, to investigate the effects of interior architecture on the mixed mode fracture behavior of 3D printed polylactic acid (PLA) components, special Arcan samples were produced at 70% filling ratio and four different filling types using fused filament fabrication technique. A special fixture has been designed that allowed the mixed-mode fracture experiments of the Arcan samples to be conducted on a unidirectional tensile test machine. The fracture tests were performed under 3 different loading angles of 0°, 45° and 90° as opening mode, mixed mode I / II and shear mode, respectively. In addition, the finite element analyses were also conducted to determine the geometric functions of the Arcan samples required for calculation of fracture toughness at different loading angles. Overall, the results of fracture toughness tests revealed that for the sections of the samples that are mainly exposed to opening and mixed-mode loading conditions, printing with the triangular filling pattern provides higher fracture toughness to the final products. In contrast, for the sections exposed to pure shear loadings, hexagonal printing pattern provides a better resistance against fracture.

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