PSI - Issue 2_A

P. Yasniy et al. / Procedia Structural Integrity 2 (2016) 3280–3287 Author name / Structural Integrity Procedia 00 (2016) 000–000

3286

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distribution of local stress range on the surface of specimen from the entrance face has been calculated. a

100 150 200 250 300 350 400 450 500 550

0% 1% 2% 3%

∆σ yy , MPa

0

1

2

3

4

5

X-d/2 , mm

b

600

0% 1% 2% 3%

550

500

450

400

350

∆σ yy , MPa

yy

300

250

200

150

0

1

2

3

4

5

X-d/2 , mm

147    MPa

Fig. 4.Normal stress range distribution on the entrance face with plane and cold expanded holes at

with diameter: (a) 8 mm; (b) 10 mm

From the obtained results follows that the highest local stress range is in the middle part along the thickness of a hole without cold expansion. So crack nucleation and propagation in the middle part of specimen at uniaxial loading occurred during experimental investigations can be explained by this fact.