Influence of printing orientation on the crack path in 3D printed tensile and shear specimens

This study investigates the mechanical behavior of 3D-printed polymer specimens subjected to tensile and shear testing, with a particular focus on the influence of raster orientation and shell contour. Specimens were produced using Fused Deposition Modelling (FDM) at three raster angles: 0, 45, and 90 degrees, and were tested using both mechanical extensometer and Digital Image Correlation (DIC) systems. The results demonstrated a significant impact of raster orientation on the tensile and shear properties, with 0° specimens showing higher tensile strength due to the alignment of the filaments with the load direction. In contrast, 45° specimens exhibited more ductile behavior. The use of shell contour showed minimal effect on 0 and 45-degree specimens but contributed to greater stiffness and ductility in 90-degree specimens. Additionally, DIC measurements closely matched the extensometer data, with the added benefit of capturing strain distribution across the entire specimen surface, which is particularly advantageous in shear tests. These findings contribute to a better understanding of the anisotropic behavior of 3D-printed materials and the importance of proper raster orientation in optimizing mechanical performance.