Evaluation of stiffness and strength in fused deposition sandwich specimens

New technologies known as additive manufacturing (AM) are now available for producing prototypes directly from a 3D CAD model. However, prototypes made by AM usually have mechanical characteristics inferior to those of the final product. AM technologies are in increasing demand for use in the development of functional prototypes and the manufacture of final products. The main aim of this work was to evaluate the influence of deposition strategies on the mechanical behavior of the AM process known as fused deposition modeling (FDM) and to gain a better understanding of the stiffness behavior of the parts. Specimens with different raster orientations in each layer (sandwich-like configurations) were built. The final stiffness and strength of the specimens were determined in tensile and bending tests, and the stiffness was predicted using classical lamination theory. The stiffness in the two main directions for the specimens manufactured with the sandwich deposition configurations was higher than or at least equal to the stiffness of the specimens produced with the default FDM configuration. However, the results indicate that the analytical model used did not accurately predict the behavior in the experimental tests.