PSI - Issue 28

Mohammad Reza Khosravani et al. / Procedia Structural Integrity 28 (2020) 720–725 M.R. Khosravani and T. Reinicke / Structural Integrity Procedia 00 (2020) 000–000

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fractured specimens are presented. As in the FDM process the components are printed layer by layer, they can be considered as transverse isotropic materials.

= 0

= 30

= 45֯

= 60

= 90֯֯֯֯

Fig. 2. Fractured specimens with di ff erent raster directions.

As can be seen in Fig. 2 in the specimen with 0 ◦ raster direction, the crack is perpendicular to the raster orientation. In other fractured specimens, the cracks are oriented with the raster direction. This issue was occured for all the specimens printed under two di ff erent speed of 20 mm / s and 80 mm / s. Based on the experimental tests, the mechanical behavior of the examined specimens were determined. Indeed, load-displacement curves were obtained and all the curves showed a linear elastic zone from which the elastic modulus can be determined. Fig. 3 shows stress-strain curves of the specimens with di ff erent raster directions and printing speeds. These curves confirmed that strength and sti ff ness depend on raster direction.

α = 0° α = 30° α = 45° α = 60° α = 90°

α = 0° α = 30° α = 45° α = 60° α = 90°

%

%

(a)

(b)

Fig. 3. Stress-strain curves of examined specimens, printed with di ff erent speeds (a) 20 mm / s; (b) 80 mm / s.