PSI - Issue 2_A

Haydar Dirik et al. / Procedia Structural Integrity 2 (2016) 3073–3080 Haydar Dirik and Tuncay Yalçinkaya / Structural Integrity Procedia 00 (2016) 000–000

3079

7

70

60

Nasgro XFEM Test Data

Nasgro XFEM Test Data

60

50

50

σ min = 3.45 MPa σ max = 68.95 MPa σ ol = 103.43 MPa m=50, n=1

40

σ min = 3.45 MPa σ max = 68.95 MPa σ ol = 103.43 MPa m=300, n=1

40

30

30

20

Crack Length [mm]

Crack Length [mm]

20

10

10

0

0

0

0.5

1

1.5

2

2.5

0

0.5

1

1.5

2

2.5

3

3.5

4

Number of Cycle

Number of Cycle

x 10 5

x 10 5

Fig. 6. Comparison of NASGRO, XFEM and Porter test data for di ff erent OL sequences.

45

35

Nasgro XFEM Test Data

Nasgro XFEM Test Data

40

30

35

σ min = 51.72MPa σ max = 103.43 MPa σ ol = 155.14 MPa σ ul = 5.17 MPa m=50, n=1

25

σ min = 51.72 MPa σ max = 103.43 MPa σ ol = 155.14 MPa σ ul = 31.03 MPa m=50, n=1

30

25

20

20

15

Crack Length [mm]

Crack Length [mm]

15

10

10

5

5

0

2

4

6

8

10

12

0

2

4

6

8

10

Number of Cycle

Number of Cycle

x 10 4

x 10 4

Fig. 7. Comparison of NASGRO, XFEM and Porter test data for di ff erent OL-UL ratios.

Fig. 8. Crack growth simulation steps for spectrum defined in Fig 3.a ( n = 1 , m = 29) ( σ min = 3 . 45, σ max = 68 . 95, σ oL = 76 . 54)

of crack propagation at four di ff erent steps using the spectrum defined in Figure 3a ( n = 1 , m = 29 ) and as expected from KII = 0 criteria crack propagates in straight ahead direction at almost zero degree.