PSI - Issue 34

Dario Santonocito et al. / Procedia Structural Integrity 34 (2021) 211–220 D. Santonocito et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 3. a) Specimen geometry and building characteristics; b) Test setup.

4. Results and Discussion 4.1. Mechanical properties

Static tensile tests were performed on three specimens of PA12, obtained by SLS process, under displacement control. The adoption of an extensometer allowed to obtain the engineering stress-strain curve of the material (Fig. 4). The curves exhibit the same trend, with an initial linear elastic part followed by a smooth hardening, where it is not possible to assess in a clear way the yielding point. To evaluate Young’s Modulus, the linear regression of the stress vs strain between ε 1 =0.0005 and ε 2 =0.0025 have been performed.

Fig. 4. Engineering curve and mechanical properties of SLS PA12.

The evaluated Young’s Moduli are lower compared to the value declared by the manufacturer (1488.6±30.3 MPa vs. 1700 MPa). The specimens exhibit an ultimate tensile strength of 42.2±0.8 MPa, lower compared to the value of