PSI - Issue 26

Cristina Vălean et al. / Procedia Structural Integrity 26 (2020) 313– 320 Vălean et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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Figure 6 shows variation of the Young’s Modulus and the tensile strength with the PO. As mentioned above, due to the almost overlap of the linear-elastic zones, the specimens have almost the same value of the Young’s Modulus. Insignificantly higher values, of only 1.18%, can be observed in the case of DB-4.00-90 specimens, compared to the DB-4.00-45 ones. Moreover, this variation of the properties can be associated with a linear trendline. An aspect to note is that for the DB-4.00-90 specimen, the highest standard deviations of the results are obtained (~ 216 MPa), while at the opposite pole is DB-4.00-45 specimen (~ 31 MPa). On the other hand, the tensile strength shows significant differences with the change of the PO. In this case, it can be seen that the highest values are found for the DB-4.00-0 specimens (50.88 MPa), while the lowest values (46.77 MPa) are presented by the DB-4.00-45 specimens. All the results, regardless of the PO, present errors below 1.5%.

Fig. 6. Influence of PO on Young’s Modulus (a) and tensile strength (b) properties

In the last part of the paper, we investigated the influence of the size effect on the main mechanical properties of the 3D printed specimens. Figure 7 shows t he variation of Young’s Modulus and tensile strength with the thickness of the tested specimens.

Fig. 7. Influence of specimen thickness on Young’s Modulus (a) and tensile strength (b) properties