In the last decade, the additive manufacturing based on fused deposition modelling (FDM) has become increasingly attractive in diverse engineering elds. For successful applications of 3D printed structural elements as end-user parts, reliable performance in terms of stiffness and strength properties has to be ensured. There are numerous experimental studies that mainly investigate the stiffness properties of the 3D printed materials as a function of several printing parameters. However, only few studies, have characterized the failure mechanisms of 3D printed samples and the crucial role of the bond properties between adjacent fibers on the overall strength of printed elements. This work aims to propose an innovative non-local orthotropic damage and plasticity phenomenological model for 3D printed materials. The effective mechanical behaviour of 3D printed structural elements is described by means of the composite laminate theory. Each layer of the laminate is described with an orthotropic elasto-plastic constitutive behaviour and the Tsai-Hill yield limit function is adopted. Moreover, the stiffness degradation of the material is described by means of three damage variables specially introduced to describe the different damage phenomena (i.e., ber failure, inter-layer and intra-layer damage) occurring under different loading conditions, as highlighted by the analysis of the 3D printed samples after the failure. Some numerical applications are carried out, comparing numerical results with the experimental ones. The proposed model proved to be able to reproduce the range of failure modes from brittle-like to ductile that characterize the mechanical behaviour of 3D printed materials.