Issue 25

V. Veselý et alii, Frattura ed Integrità Strutturale, 25 (2013) 69-78; DOI: 10.3221/IGF-ESIS.25.11

P v is neglected, significant difference appears earlier, around  = 0.75 (see Fig. 6a and b, where comparison with [23], which ignores P v , is shown).

(a) (b) (c) (d) Figure 4 : 2D representation of the WST – static scheme with indication of boundary conditions (a) and corresponding FE model (b) . Example of the FE mesh around the crack tip: ring of selected nodes (at radius 5 mm from the crack tip) (c) and quarter-point crack tip elements (d) .

1.75

200

platens I, P sp platens I, P sp platens I, P sp platens I, P sp platens II, P sp platens II, P sp

platens I, P sp platens I, P sp platens I, P sp platens I, P sp platens II, P sp platens II, P sp

1.50

175

+ P v + P v + P v

, 1 supp.

+ P v + P v + P v

, 1 supp.

, 2 supp. (1/4) , 2 supp. (1/8)

, 2 supp. (1/4) , 2 supp. (1/8)

1.25

150

1.00

+ P v + P v

, 1 supp.

+ P v + P v

, 1 supp.

125

, 2 supp. (1/4)

, 2 supp. (1/4)

0.75

100

B 1 [-]

B 2 [-]

0.50

75

0.25

50

0.00

25

-0.25

0

-0.50

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

α [-]

α [-]

(a)

(b)

and B 2 as functions of the relative crack length  for various considered boundary conditions.

Figure 5 : Geometry factors B 1

300

2500

(a)

(b)

250

0

200

-2500

-5000

150

g 7 [-]

g 4 [-]

-7500

100

-10000

50

(c)

(d)

-12500

0

-15000

-50

0.2 0.4 0.6 0.8

0.850 0.875 0.900 0.925 α [-]

0.2 0.4 0.6 0.8

0.7

0.8

0.9

α [-]

α [-]

α [-]

platens II, P sp platens II, P sp

+ P v + P v

, 1 supp.

platens II, P sp platens II, P sp distrib. load, P sp

+ P v + P v

, 1 supp.

, 2 supp. (1/4)

, 2 supp. (1/4)

, 2 supp. (1/4) (ref. Karihaloo et al. 2003)

Figure 6 : Shape functions g 4 as functions of the relative crack length  for two support variants. An accurate knowledge of the mechanical fields in the cracked body is necessary for a relevant fracture analysis. As an example, a reconstruction of the stress fields in the WST (platens II, one support, P v considered) is introduced. Fig. 7 and g 7

75

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