PSI - Issue 77

Sergio Cicero et al. / Procedia Structural Integrity 77 (2026) 56–63 Sergio Cicero et al./ Structural Integrity Procedia 00 (2026) 000 – 000

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considered. The two composites present higher fracture toughness than the corresponding pristine polymers, but the notch effect in the composites does not follow a clear pattern when compared to that observed in the polymers. Finally, one of the PLA orientations, 45/-45, is particularly interesting, as it generates a notch effect significantly greater than the other cases. For this orientation the value of the critical distance (L) is 0.15 mm, and the increase in fracture resistance for notch radii of 2 mm is above 100%.

12.0

10.0

8.0

1/2 )

6.0

4.0 K N mat (MPa·m

2.0

0.0

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

ρ 1/2 (mm 1/2 ) ABS 45/-45 PLA 45/-45 ASA 45/-45 ABS 45/-45 fit PLA 45/-45 fit ASA 45/-45 fit

ABS 0/90 PLA 0/90 ASA 0/90

ABS 30/-60 PLA 30/-60 ASA 30/-60

ABS 0/90 fit PLA 0/90 fit ASA 0/90 fit

ABS 30/-60 fit PLA 30/-60 fit ASA 30/-60 fit

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 K N mat (MPa·m 1/2 ) ρ 1/2 (mm 1/2 )

PLA-Gr 0/90 ASA-CF 0/90 PLA-Gr 0/90 fit ASA-CF 0/90 fit

PLA-Gr 45/-45 ASA-CF 45/-45 PLA-Gr 45/-45 fit ASA-CF 45/-45 fit

PLA-Gr 30/-60 ASA-CF 30/-60 PLA-Gr 30/-60 fit ASA-CF 30/-60 fit

Figure 2. Apparent fracture toughness results and best fit using the Line Method (equation (4)). a) polymeric materials ABS, PLA and ASA; composite materials PLA-Gr and ASA-CF.