PSI - Issue 56

Alexandru Isaincu et al. / Procedia Structural Integrity 56 (2024) 167–175 Alexandru Isaincu / Structural Integrity Procedia 00 (2019) 000 – 000

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orientation and crack orientation. This remark is important if the results are compared with different shapes of the specimen in which the fiber orientation angle relative to the melt flow is not visible.

a)

b)

c)

d)

Fig. 2. a) SEC specimen dimensions and the fiber orientation angle in relation to crack orientation for 90° in b), for 45° in c) and for 0° in d).

2.3. Tensile tests on dog bone specimens To characterize the behavior of the two materials, tensile tests were performed on dog bone specimens. The testing was performed according to ISO 527. Type 1BA specimens were cut from the previous mentioned plates as for SEC specimens. The tensile tests were performed for both thicknesses of the materials. The following orientation angles were considered for testing: 0°,15°,30°,45°,60° and 90°. An overview of the mechanical properties can be found in Micota, Isaincu and Marşavina (2021 ). The main properties are presented in Table 1.

Table 1. Mechanical properties for PPA GF33 and PPS GF40 for two thicknesses (2.0 mm and 3.2 mm).

Material

Thickness [mm]

Orientation Angle [°]

Young’s Modulus [MPa]

Tensile Strength [MPa]

Strain at break [%]

PPA

2.0

0

11698

186.4 110.4

2.20 5.13 5.02 2.83 3.74 3.57 1.56 2.17 1.79 1.45 1.45 1.28

GF33

45 90

6510 5616 8996 6980 6363

96.0

3.2

0

146.6 125.2 111.3 194.6 121.2

45 90

PPS

2.0

0

15923

GF40

45 90

8649 7385

98.4

3.2

0

11693

134.1 105.8

45 90

9051 9191

98.3

A clear decrease in rigidity, resistance and ductility in between the two thicknesses can be distinguished for both materials. 2.4. Tensile tests on SEC specimens To investigate the toughness of the two materials, a series of tensile tests were performed on SEC specimens. These tests were conducted under mode I (crack opening) loading conditions. All tests were conducted at room temperature (≈20°C) and in normal humidity conditions (50% R.H.). A vertical tensile force (F) was applied up to fracture. A