PSI - Issue 35

4

Kadir Bilisik et al. / Procedia Structural Integrity 35 (2022) 210–218 Author name / StructuralIntegrity Procedia 00 (2019) 000 – 000

213

m

P

12   m

2

A

(1)

12 x y     

(2)

 

 

G



12

12

(3)

12

Fig. 2. (a) In-plane shear sample in the universal testing machine equipped with video extensometer, (b) in-plane shear sample illustrates material axis and specimen axis, schematic, Bilisik et al. (2019c).

2.3. Interlaminar Fracture Toughness (G IIC ) Test Interlaminar fracture toughness (mode-II type) of the aramid composite was experimentally defined by considering the American Society for Testing and Materials D7905‒14 which was based on the end notch flexure sample geometry (ENF), ASTM D7905‒14. Mode -II test is depicted in Figure 3(a-b) where a o and a i are the delamination length (mm) and initial insert length (45 mm), respectively, Adams et al. (2003). Data reduction on the identifying the G IIC was accomplished via the compliance calibration (CC) method considering equation (4). On the other hand, the maximum load point was used to find the G IIC using the equation (5), ASTMD7905‒14 and Adams et al. (2003). Where, the slope of the linear fit of compliance versus crack length cubed was coded as m , the sample width (mm) was represented as B . Reference (Bilisik et al. 2020) included complete information on the testing procedure.

3 C A ma  

(4)

2 mP a Max

2

3

G



0

IIC

2

B

(5)

The aramid nanocomposite densities were identified by following the American Society for Testing and Materials D792-91 , ASTM D792‒91 . In addition, the volume fractions of aramid nanocomposites were found by American Society for Testing and Materials D3171-99, ASTM D3171-99. The scanning electron microscope (FESEM, ZEISS GeminiSEM500, Germany) and an optical microscope (Olympus SZ61, JP equipped with Bs200DOC digital image analysis software-Bs200DOC, TR) were utilized to identify the fracture morphology of the composite samples.