This work analyses the performance of parts built by Additive Manufacturing (AM) using fused filament fabrication (FFF) demonstrating the correlation between the printing orientation and structural performance. FFF components present two regions showing different mechanical behaviour: the external contour and the inner structure (in-fills or lattice). The respective mechanical properties of the contour and the inner structure are obtained. In this work the inner structure is replaced by an anisotropic homogenized material. A Representative Volume Element with Periodic Boundary conditions is adopted to obtain the corresponding equivalent constitutive tensor. On the other hand, the contour is considered isotropic. The material characterization of both the in-fill and the contour is done following two complementary strategies: (1) an experimental campaign involving several tensile tests on FFF specimens; (2) a sensitivity analysis through numerical modelling. Performing experiments to obtain the material properties for contour and in-fill may be a challenging task. Thus, the numerical modelling and the optimization technique are used to obtain the material properties as a function of the filament properties. Calibration of the structural response of 3D-printed demonstrators under bending and torsion is done in order to optimize the material parameters of the numerical model by minimising the difference between the experimental and numerically computed structural stiffness. It is shown that assuming isotropic behaviour for the contour results in a negligible error. The AM software so calibrated can be used for analysing the mechanical performance of FFF components and selecting the optimal printing orientation as well as the contour thickness and in-fill density to satisfy the structural performance required.

这项工作使用熔融长丝制造（FFF）分析了增材制造（AM）制造的零件的性能，证明了印刷方向与结构性能之间的相关性。FFF组件具有两个显示不同机械行为的区域：外部轮廓和内部结构（填充或晶格）。获得轮廓和内部结构的相应机械性能。在这项工作中，内部结构被各向异性的均质材料所替代。采用具有周期性边界条件的代表体积单元来获得相应的等效本构张量。另一方面，轮廓被认为是各向同性的。填充和轮廓的材料特征描述遵循以下两种互补策略：（1）一项涉及FFF试样的多次拉伸试验的实验活动；（2）通过数值建模进行敏感性分析。进行实验以获得轮廓和填充的材料特性可能是一项艰巨的任务。因此，数值建模和优化技术被用来获得材料特性作为长丝特性的函数。进行了3D打印示威者在弯曲和扭转下的结构响应的校准，以通过最小化实验和数值计算的结构刚度之间的差异来优化数值模型的材料参数。结果表明，假设轮廓的各向同性行为导致的误差可忽略不计。