PSI - Issue 61

Enes Günay et al. / Procedia Structural Integrity 61 (2024) 34–41 E. Gu¨nay et al. / Structural Integrity Procedia 00 (2024) 000–000

37

4

indenter moves across the material surface to simulate the scratching test. The indentation and scratching directions are shown in Fig. 1c. Encastre boundary conditions are applied to all but one surface of the sample, which is the free surface where the contact between the indenter and the sample is defined, as shown in Fig. 1d. The contact is modeled as a finite sliding, surface to surface contact with a friction coe ffi cient of 0.15 (see Kareer et al. (2020)). Displacement magnitudes and dimensions of all samples are given in Table 1. The crystal plasticity parameters of the face-centered cubic copper are given in Table 2.

(a) Grain structure

(b) Mesh of the specimen

(c) Indentation and scratching directions

(d) Boundary conditions

Fig. 1: Finite element method model details

Table 1: Model dimensions and prescribed displacements

Average grain diameter

Single crystal

5 µ m

15 µ m

50 µ m

Length in x-direction (scratching dir.) Length in y-direction (indentation dir.)

25 µ m 7.5 µ m 15 µ m

20 µ m 2.5 µ m 10 µ m

60 µ m 7.5 µ m 30 µ m

200 µ m 25 µ m 100 µ m 2.47 µ m

Length in z-direction

Indentation depth Indentation rate Scratch distance Scratching rate

0.247 µ m

0.247 µ m

0.741 µ m

0.247 µ m / s

0.247 µ m / s

0.741 µ m / s

2.47 µ m / s

10 µ m

5.6 µ m

16.8 µ m 30 µ m / s

56 µ m

10 µ m / s

10 µ m / s

100 µ m / s

Table 2: Crystal plasticity material parameters of copper taken from Wang et al. (2019b) and Zhang et al. (2006)

C 11

C 12

C 44

˙ γ 0

n q

h 0

g s

g 0

b

G

α

10 -3 GPa

0.3 2.5*10 -7 mm

168.4 GPa

121.4 GPa

75.4 GPa

13 1.4 110 MPa

100 MPa

32 MPa

45 GPa