Fatigue Crack Paths 2003

deviation, does not return to its initial plane. A crack, for example, in a eight-petal

specimen under biaxial tension with K=0.5 and =0q is directionally unstable in this

0 E

sense, and a typical crack path is shown in Fig.4,a. Moreover, for these specimens under

biaxial loading the amount of crack path curvature (Fig.4,b) is a function of the tensile

properties of the aluminum alloys concerned Table 1.

4.25

16.

25

A M G 6

A M G 6

V V 0 =0.06

a E G P m = 0 0 o

V V 0 =0.06 a /w=0.3 0 w = 8 0 m m K = 0.5

b

1.35 1.40 1.45 1.50 1.55 C R A CLKE N G TIHN C R E M E N T 3.0205

.0205

C R A CLKE N G TIHN C R E M E N T

a /w=0.3 0 w = 8 0 m m K = 0.5

4.00

16

.00

15

.75

3.75

3.50

15

.50

E0 = 65o

9.50

10.00

10.50

11.00

G P m

15

Figure 4. Computational predictions for the fatigue crack path at the microscale level

Thus, the influence of the geometry specimens, the initial crack length and the

material properties were studied. Attention is focused on the mixed-mode crack

trajectories.

The behavior of the crack path under mixed-mode fracture is discussed

with regard to microscopic and macroscopic scales.

R E F E R E N C E S

1. Shlyannikov, V.N. (2003) Elastic-Plastic Mixed-Mode Fracture Criteria and

Parameters, Springer.

2. Richard, H.A. and Benitz, K. (1983) Jnt. J. Fract. 22, R55-R58.

Shlyannikov, V.N. (1996). Theoret. Appl. Fract. Mech. 25, 187-201.

3.

4. Shlyannikov, V.N. and Dolgorukov, V.A. (1987). Industr. Lab. 53, 749-754.