PSI - Issue 28

S. Cicero et al. / Procedia Structural Integrity 28 (2020) 84–92

91

8

Cicero et al./ Structural Integrity Procedia 00 (2019) 000–000

the FMC-ASED model provides satisfactory predictions of the test results. In most cases, the accuracy of the predictions is good and in only two cases, the accuracy is low. By considering all the test data simultaneously, the average discrepancy for the FMC-ASED model is obtained to be equal to 12.7%, something reasonable in the fracture mechanics context, demonstrating the effectiveness of this model and suggesting that this model can be utilized as an efficient criterion for fracture prediction of notched components with nonlinear behavior. Table 2. Experimental results for SGFR-PA6 (10 wt.%). M c : moisture content; a: crack length; P max : maximum load; A pl : plastic area; ρ: notch radius; a=5 mm for non-crack defects (ρ=0.25 mm up to ρ=2.00 mm).

ρ = 0 mm

ρ = 0.25 mm

ρ = 0.50 mm

ρ = 1.00 mm

ρ = 2.00 mm

M c (%)

A pl (N ꞏ mm)

P max (N)

P max (N)

P max (N)

P max (N)

P max (N)

A pl (N ꞏ mm)

A pl (N ꞏ mm)

A pl (N ꞏ mm)

A pl (N ꞏ mm)

a (mm)

4.55 4.40 4.37 4.38 4.25 4.54 4.35 4.59 4.61

157.9 160.7 173.8 161.1 188.1 147.1 161.7 153.8

5.76 6.05 7.84 4.97 9.49

150.9 143.0 146.9 139.5 145.7 138.1 134.6 141.8 140.4 137.0

11.70

145.30 161.40 140.01 136.10 132.30 137.00 131.20 124.10 127.00

11.76 14.69 16.78

136.3 150.2 154.7 159.0 143.9

11.70 12.63 17.62 22.30 12.94

145.4 146.0 133.1 159.3 160.4

17.05 19.97 10.17 17.57 33.60

6.48

2

12.82

9.17 7.40

9.07 8.85

63.54 70.18 53.91

69.13 45.36 71.13 86.15 74.77

82.63

152.9 207.87 168.0 377.90 154.9 199.76 139.6 106.55 152.3 179.00 152.7 160.38 148.5 140.20 156.7 254.66

152.90 129.71

73.47 44.05 71.31

5

164.0 104.02

165.0 282.34

non-valid

non-valid

Table 3. Properties of the fictitious material for different moisture contents. Moisture content (%) ɛ � (%) υ ����� (MPa) ��� (MPa) � ��� 18.62 0.38 9.91 571.64 106.44 3.87

(MPa) � ��� (MPaꞏm 0.5 ) ����� (mm) ������ (MPa)

2 5

0.406 0.958

9.91 8.79

22.72 0.38 8.79 340.45

77.35

4.32

Table 4. Estimations of fracture loads (P FMC-ASED ) obtained using FMC-ASED criterion Moisture content (%) ρ (mm) P Exp.ave (N) ASED FMC (MPa) P FMC-ASED (N) Discrepancies (%)

5.6 4.6 0.3 7.4

0.25

145.20 143.02 148.82 148.84 138.38 134.44 152.15 156.40

4.22E-04 4.43E-04 4.45E-04 3.88E-04 2.68E-04 2.73E-04 2.91E-04 3.21E-04

153.29 149.63 149.30 159.83 180.95 179.46 173.73 165.53

0.5

2

1 2

30.8 33.5 14.2

0.25

0.5

5

1 2

5.8

12.7

Average discrepancy