PSI - Issue 61

Bahman Paygozar et al. / Procedia Structural Integrity 61 (2024) 232–240 Paygozar et al./ Structural Integrity Procedia 00 (2019) 000 – 000

234

3

bending experiments were done to extract the fracture toughness of the specimens manufactured in three different print orientations. The XFEM was used to simulate the Mode-I fracture of the specimens. Then, the XFEM results were compared with the experimental results for validation. Furthermore, the digital image correlation (DIC) method was utilized to extract the mechanical properties of the samples to be used in the XFEM analyses.

2. Experimental work 2.1. Specimen preparation

SENB specimens used in the study for Mode-I fracture investigation with 3P bending tests were additively manufactured using the FFF technique as per standard ASTM D 5045-99 standard and with three repetitions in three different print orientations (i.e., lateral, horizontal, and vertical) as seen in Fig.1. The layup sequence was chosen along the z-direction and raster angle of printing in each layer was considered as ±45°, which reflects better mechanical properties (Zhang et al. 2019).

Fig.1 Different print orientations, (a) lateral, (b) horizontal, and (c) vertical, were utilized to fabricate the SENB specimens. The support was utilized to create the notch in vertically printed specimens.

It is worth mentioning that extra support was utilized to create the crack in the vertically printed specimens. The crack tip was prepared in each sample using an ultra-fine blade (SUIZAN Dozuki Dovetail Blade, Japan). The specimens were manufactured from Polylactic acid (PLA) using fused filament fabrication in an FFF machine (Zaxe X3). The process parameters utilized in fabricating the specimens are listed in Table 1 (Paygozar and Gorguluarslan 2023b and c).

Table 1. Process parameters used when manufacturing the PLA specimens. Print Temp. (°C) Bed Temp. (°C) Print speed (mm/s) Layer thickness (mm)

Line width (mm)

Fan speed 100%

Raster angle

215

60

50

0.2

0.45

± 45°

Fig.2 Geometrical parameters (a) and loading configuration (b) of the SENB specimens used in the study.