PSI - Issue 17

Hayder Al-Salih et al. / Procedia Structural Integrity 17 (2019) 682–689 Al-Salih/ Structural Integrity Procedia 00 (2019) 000 – 000

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Table 2. Horizontal branch length characterization

90% Convergence

95% Convergence

Load Case

Crack Length, mm (in.)

Crack Length, mm (in.)

Error, %

Error, %

LC1 LC2 LC3 LC4 LC5 LC6 LC7

N/A

N/A

N/A

N/A

50.2 (1.98) 50.2 (1.98) 51.2 (2.02) 51.8 (2.04) 60.9 (2.40) 63.2 (2.49) 54.6 (2.15)

-33 -33 -32 -31 -19 -16 -27

65.5 (2.58) 64.7 (2.55) 64.3 (2.53) 64.4 (2.54) 71.9 (2.83) 73.8 (2.90) 67.4 (2.65)

-13 -14 -14 -14

-4 -2

Average

-10

5.3. Vertical Branch Characterization Results

Relative displacement along the vertical branch crack path for all load cases is shown in Fig. 5a, and convergence values are presented in Fig. 5b. The optically measured crack length of 90.3 mm (3.55 in.) is indicated by the vertical dotted lines. Again, load case 1 convergence values are not presented as small displacements cause extreme variability. It can be seen that for most load cases relative displacement values approach zero well before the tip of the crack causing convergence values to greatly under-predict crack length.

Fig. 5. Vertical branch a) Relative displacement and b) Convergence of relative displacement

Table 3. Vertical branch length characterization

90% Convergence

95% Convergence

Load Case

Crack Length, mm (in.)

Crack Length, mm (in.)

Error, %

Error, %

LC1 LC2 LC3 LC4 LC5 LC6 LC7

N/A

N/A

N/A

N/A

51.0 (2.01) 50.2 (1.98) 51.3 (2.02) 51.9 (2.04) 53.7 (2.11) 54.3 (2.14) 53.0 (2.05)

-44 -44 -43 -43 -40 -40 -42

56.3 (2.22) 54.3 (2.14) 54.7 (2.15) 55.0 (2.17) 57.0 (2.24) 57.5 (2.26) 55.8 (2.20)

-38 -40 -39 -39 -37 -36 -38

Average