In this paper, a numerical method is proposed to simulate the mechanical behavior of a new polymeric pre-structured material manufactured by fused filament fabrication (FFF), where the filaments are oriented along the principal stress directions. The model implements optimized filament orientations, obtained from the G code by assigning materials references in mesh elements. The Gauss points are later configured with the physical behavior while considering a homogeneous solid structure. The objective of this study is to identify the elastoplastic behavior. Therefore, tensile tests were conducted with different filament orientations. The results show that using appropriate material constants is efficient in describing the built anisotropy and incorporating the air gap volume fraction. The suggested method is proved very efficient in implementing multiplex G code orientations. The elastic behavior of the pre-structured material is quasi-isotropic. However, the anisotropy was observed at the yield point and the ultimate stress. Using the Hill criterion coupled with an experimental tabular law of the plastic flow turns out to be suitable for predicting the response of various specimens.

Additive manufacturing (AM) is a promising way to produce complex structures by adding layers. It arises great interest both in industrial and academic sectors to develop new advanced structured material. To benefit from its advantages, it is important to accurately characterize the obtained structures in order to ensure their integrity during operation. It becomes then important to characterize these structures at the local scale (micron and/or the nanometer scale). In the specific case of polymeric materials obtained by Fused Deposition Modeling (FDM), the comprehension of the mechanical behavior between adjacent layers during deformation can help improving mechanical properties. However, few studies in the literature have focused on implementing approaches to characterize local strains at the surface of these materials. In this study, an original approach based on the use of speckle pattern with particle average size of 20 microns in diameter was coupled to digital image correlation (DIC). It has been applied to the case of a SENT structure with a notch made by FDM. The successive images recorded by a digital microscope allow a qualitative analysis of the evolutions of the local strains. The kinematic fields are obtained by DIC. The strain evolutions at the tip of the notch are highlighted. The deformation mechanisms at the local scale are confronted with macroscopic behavior of the structure.