PSI - Issue 14

Sanjeev M Kavale et al. / Procedia Structural Integrity 14 (2019) 584–596 Sanjeev M. Kavale, Krishnaraja G Kodancha, Nagaraj Ekbote / Structural Integrity Procedia 00 (2018) 000–000

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A typical variation of K I for SENB and CT specimens for different Poisson’s ratio with a/W = 0.50 and thickness B = 3mm and 25.4mm is shown in Fig. 3 and Fig. 4 respectively. A typical variation of K I for SENB and CT specimens for different Poisson’s ratio with a/W = 0.50 and B/W = 0.50 is shown in Fig. 5. These figures indicate that the magnitude of K I is increasing with the increase in Poisson’s ratio. It is also observed that the difference in the magnitude of K I between surface and the center for the specimen with higher Poisson’s ratio is more as compared to the specimen with lesser Poisson’s ratio. Also, the difference in the magnitude of K I between surface and the center for the specimen is increasing with increasing thickness of the specimen irrespective of the Poisson’s ratio. Therefore, the specimen with higher Poisson’s ratio experiences higher crack-tip constraint at the center than specimens with lower Poisson’s ratio. Hence the material with the higher Poisson’s ratio may fail earlier as compared to material with lower Poisson’s ratio. Also it is observed that as the value of Poisson’s ratio reduces to zero, the magnitude of K I becomes equivalent to the value of 2D Plane Strain K I across the thickness. Similar observations are made by Pavel et al. (2010). The values obtained through 3D FE analyses are validated with Kudari and Kodancha (2014, 2017) and Kwon and Sun (2000) for SENB and CT specimen. A maximum error of 4.4% and 3.29% is observed between the FE values and available literature for SENB and CT specimen respectively.

0.20 (B)

(A)

0.15

0.5

0.10

0.0

 = 0.20  = 0.25  = 0.30  = 0.35  = 0.40  = 0.45

0.05

T 11 / 

T 11 / 

 = 0.20  = 0.25  = 0.30  = 0.35  = 0.40  = 0.45

SENB a/W=0.50 B=3mm

SENB a/W=0.50 B=25.4mm

-0.5

0.00

-0.05

-1.0

-1.50

-0.75

0.00

0.75

1.50

-15 -10

-5

0

5

10

15

B in mm

B in mm

Fig. 6 Variation of T 11 in SENB specimen along the crack-front for various Poisson’s ratio and specimen thickness (A) 3mm and (B) 25.4mm

(B)

1.5 (A)

 = 0.20  = 0.25  = 0.30  = 0.35  = 0.40  = 0.45

0.84

CT a/W=0.50 B=25.4mm

1.2

0.80

0.9

0.76

0.6

 = 0.20  = 0.25  = 0.30  = 0.35  = 0.40  = 0.45

0.72

T 11 / 

T 11 / 

CT a/W=0.50 B=3mm

0.3

0.68

0.0

0.64

-0.3

0.60

-15 -10

-5

0

5

10

15

-1.5 -1.0 -0.5

0.0

0.5

1.0

1.5

B in mm

B in mm

Fig. 7 Variation of T 11 in CT specimen along the crack-front for various Poisson’s ratio and specimen thickness (A) 3mm and (B) 25.4mm

On the similar lines, variation of T 11 for SENB and CT specimens for different Poisson’s ratio with a/W = 0.50 and thickness B = 3mm and 25.4mm are shown in Fig. 6 and Fig. 7 respectively. A typical variation of T 11 for SENB