## 3 Experimental Setups
### Tensile Tests Results  
For every performed tensile test, the calculated Young's modulus value will indirectly take into account the existing air gap by computing the engineering stress via the geometrical section. The calculations are made with respect to the D638 ASTM norm [26]: Young's modulus is calculated as the slope of the tangent to the true stress-strain curve at low stress. To get such a curve, the assumption of volume conservation was made since the volume variation data is not available. The DIC analysis gives an estimation of the average value of the transversal and the longitudinal strain, which are used to calculate the Poisson's ratio values. The yield strength is calculated via the 0.2% strain offset method. The results are displayed in Table 2.  
The experimental tensile curves show that the material exhibits different behaviors according to the filament orientation (see Figure 5). For the 90\({}^{\circ}\) orientation, the elongation at break is almost equal to the elongation at yield strength. Thus, the behavior can be assumed perfectly elastic with a brittle fracture. On the other hand, the 0\({}^{\circ}\) specimens \begin{table}
\begin{tabular}{c c} \hline
**Printing Configuration** & **Built Flat** \\ \hline Layer thickness & 0.25 mm (0.35 for the first one) \\ Extrusion temperature & 235 \({}^{\circ}\)C \\ Built plate temperature & 120 \({}^{\circ}\)C \\ Thread diameter & 1.7 mm \\ Infill density & 100\% \\ Material & ABS (white) \\ \hline \end{tabular}
\end{table} 
Table 1: Printing settings. \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Orientation** & \multicolumn{2}{c}{**0\({}^{\circ}\)**} & \multicolumn{2}{c}{**90\({}^{\circ}\)**} & \multicolumn{2}{c}{**45\({}^{\circ}\)**} \\ \cline{2-7}  & **Mean** & **Std \({}^{*}\)** & **Mean** & **Std** & **Mean** & **Std** \\ \hline Young’s modulus (MPa) & 1680 & 71 & 1414 & 133 & 1484 & 53 \\ Offset yield strength 0.2\% (MPa) & 23.54 & 1.59 & 13.3 & 0.78 & 17.53 & 0.95 \\ Tensile strength (MPa) & 28.67 & 0.79 & 13.86 & 0.65 & 20.25 & 1.16 \\ Elongation at fracture (\%) & 4.90 & 1.31 & 1.12 & 0.18 & 3.65 & 0.46 \\ Poisson’s ratio & 0.371 & 0.032 & 0.312 & 0.032 & 0.342 & 0.028 \\ \hline \end{tabular} \({}^{*}\) Std: standard deviation.  
\end{table} 
Table 2: Results of tensile tests. display the highest tensile strength of 23.54 MPa since the loading is directly applied on the longitudinal direction of the filament considered as the strongest direction. Here the behavior has a pronounced plastic behavior directly linked to a ductile fracture. In addition, a softening was observed in this direction. This softening behavior can be explained by referring to the work of [PERSON] et al. (2018). In fact, ABS material exhibits a strain-softening behavior at a low strain rate, which was around 10\({}^{-4}\) s\({}^{-1}\) for the tensile tests. Finally, the 45\({}^{\circ}\) specimen displays an intermediary behavior between both 0\({}^{\circ}\) and 90\({}^{\circ}\) with an almost elastic perfectly plastic behavior. The yield strength is found equal to 17.53 MPa. The fracture is also ductile and occurs at a 45\({}^{\circ}\) angle at the welding line direction. These findings are coherent with the work of [PERSON] et al. (2018) which showcased the same behavior for the studied orientations. [PERSON]'s modulus is slightly lower but this can be explained by the difference in the extrusion temperature. The extrusion temperature used to fabricate the specimen is 235 \({}^{\circ}\)C while the temperature of extrusion used by [PERSON] was around 255 \({}^{\circ}\)C. A higher extrusion temperature enhances the bonding between the filament and thus, the mechanical stiffness increases ([PERSON], 2018). For the Poisson's ratio of the 0\({}^{\circ}\) oriented sample, the same value was found by [PERSON] et al. (2018). For the yield strength, [PERSON] (2018) found a yield strength equal to 26.3 MPa, 14.6 MPa, and 18.54 MPa while the authors found 23.54 MPa, 13.3 MPa, and 17.53 MPa for 0\({}^{\circ}\), 90\({}^{\circ}\), and 45\({}^{\circ}\) respectively.