PSI - Issue 28

Giovanni Pio Pucillo et al. / Procedia Structural Integrity 28 (2020) 2013–2025 GP Pucillo et al. – Part II / Structural Integrity Procedia 00 (2019) 000 – 000

2022 10

The comparison between hoop maximum strains measured by strain gauges and by finite element simulation is presented in Fig. 13, where it is found that numerical results agree well with experimental ones. The comparison between predicted radial strains and measured ones is shown in Fig. 14. Also in this case, a good agreement is observed for both maximum and residual strains. In summary, it is possible to appreciate a good agreement between the experimental results and the FE predictions; this guarantees the validation of the finite element model proposed in this study, which may be used for the development of an LEFM-based methodology for crack growth prediction at cold-expanded holes.

Hoop maximum strain at 0

Hoop maximum strain at +45

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000 0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000

FEM Experimental hole #6 Experimental hole #5 Experimental hole #2

FEM

Experimental hole #6 Experimental hole #2

Strain [μ m/m]

Strain [μ m/m]

0

10 20 30 40 50

0

5

10

15

20

Distance from hole edge [mm]

Distance from hole edge [mm]

Hoop maximum strain at +90

Hoop maximum strain at -90

Hoop maximum strain at -45

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000

0 2000 4000 6000 8000 10000 12000 14000 16000 18000 20000 22000

FEM

FEM

FEM

Experimental hole #2

Experimental hole #2

Experimental hole #6

Strain [μ m/m]

Strain [μ m/m]

Strain [μ m/m]

Distance from hole edge [mm] 0 5 10 15 20

0

10

20

0 5 10 15 20 Distance from hole edge [mm]

Distance from hole edge [mm]

Fig. 13. Comparison of measurement results and simulation results of hoop maximum strains along directions at 0°, ±45°, and ±90°.

0 5 10 15 20 Radial residual strain at +90

Radial residual strain at 0

0 5 10 15 20 Radial maximum strain at +90

0

10

20

-30000 -27500 -25000 -22500 -20000 -17500 -15000 -12500 -10000 -7500 -5000 -2500 0

-30000 -27500 -25000 -22500 -20000 -17500 -15000 -12500 -10000 -7500 -5000 -2500 0

-30000 -27500 -25000 -22500 -20000 -17500 -15000 -12500 -10000 -7500 -5000 -2500 0

Strain [μ m/m]

Strain [μ m/m]

Strain [μ m/m]

FEM Experimental hole #2 Experimental hole #6

FEM

FEM Experimental hole #6

Experimental hole #6

Distance from hole edge [mm]

Distance from hole edge [mm]

Distance from hole edge [mm]

Fig. 14. Comparison of simulation results and measurement results of radial maximum strains along the direction at +90° and of residual strains along directions at +90° and 0°.