PSI - Issue 21

Emre Kurt et al. / Procedia Structural Integrity 21 (2019) 21–30 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Fig. 7. Geometry and crack dimensions of the specimen containing multiple cracks (Shu et al. (2017)).

Multiple fatigue crack propagation analyses are performed for the 10 mm-thick specimen under 42 kN tensile load. In Fig. 8, the overall view of finite element model and close-up view of crack front are shown. JUL 1 2019 17:06:10 EMENTS 1 ELEMENTS

JUL 1 2019 17:08:55

1

ELEMENTS

JUL 1 2019 17:08:55

1

ELEMENTS U F

JUL 2 2019 00:58:47

NFOR RFOR

y

x

z

Fig. 8. The overall view of finite element model and close-up view of crack front

As is the case with the first application model, the finite element models have hexahedral enriched and transition elements along and near the crack front and tetrahedral elements elsewhere. The fatigue crack growth-related material properties, C and n used in the analyses are 9.194·10 -9 (mm/cycle·(Pa·mm 0.5 )) and 2.82, respectively. Modulus of elasticity and Poisson’s ratio are E = 190 GPa and v = 0.3. In Fig. 9, distributions of mixed mode SIFs along the crack front obtained for both cracks from each propagation step using FCPAS are presented.

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00 100.00

crack-1

crack-2

23rd crack front

23rd crack front

K I (MPa·m½)

K I (MPa·m½)

Pre-crack

Pre-crack

0

0.2

0.4

0.6

0.8

1

0

0.2

0.4

0.6

0.8

1

Nondimensional position, s

Nondimensional position, s

(a)