In this work the mechanical performance and the fracture mechanics of Fused Filament Fabrication (FFF) components are analyzed. Different cracking mechanisms present in the failure of FFF polymeric parts are identified and represented in a computational model equipped with an appropriate failure criterion. Finite Element (FE) simulations are performed for different printing orientations and an isotropic damage model is applied. A multiscale orthotropic material model previously tested and validated in [1, 2] is used to characterize the mechanical behavior of the FFF components in both the elastic and inelastic regimes. This approach allows to distinguish between the different printing patterns present in a FFF component and to define their mechanical properties accordingly. The cracking behavior is characterized with the Tsai-Wu failure criterion due to the orthotropy and heterogeneity constitutive nature of FFF components as well as different strengths under tension and compression. A novel direction-dependent fracture energy model is implemented in order to properly capture the brittleness of the incipient cracking mechanisms and the filament-to-filament adhesion. Experimental test results are used to calibrate and to validate the developed model.