PSI - Issue 40

V. Kibitkin et al. / Procedia Structural Integrity 40 (2022) 223–230

228

6

V. Kibitkin et al/ Structural Integrity Procedia 00 (2022) 000 – 000

 n * 10

4 , 1/s

4 , mkm/s

 n * 10

4.0

III

II

I

II

I

III

7

3.5

3.0

6

2.5

5

2.0

4

1.5

3

1.0

t, s

t, s

50

100

150

200

250

50

100

150

200

250

a

b

Fig. 5. Dependences of the average  n (a) specific deformation and  n (b) variance on time.

The data shown in Fig. 6 were obtained by averaging over the entire observed area of the sample. However, strictly speaking, not all areas of a given region are the same in terms of the stress-strain state. Let's divide the observation area into nine areas of approximately the same size. Let us look at the most representative of them: A, B, C, D. It can be seen that, indeed, in the central region, the average strain rate remains the highest within the first stage, and then it gives way to the leadership of region C. Over time, deformation begins to prevail in the corner regions of the specimen (B). In this case, the deformation in the remaining areas is gradually equalized in amplitude and becomes more uniform.

 n * 10

3 , mkm/s

 n * 10

4 , 1/s

10

3

3

8

1

2

6

2

1

3

2

4

1

2

4

4

0

0

t, s

t, s

0

50

100

150

200

0

50

100

150

200

a

b

Fig. 6. Evolution of the average specific deformation  n (a) and variance  n (b), averaged over the areas. 1 - А area, 2 - В area, 3 - C area, 4 - D area.