Symmetric branching was found in all fatigue experiments carried out in a cruciform specimen in which the initial crack was in the middle of the specimen and at 45 deg with respect to the loading axes. The loading was biaxial, sinusoidal along each axis and out-of-phase from each other. Stress intensity factor calculations using finite element methods showed ΔKII was almost zero along each branch for all four branches so that all branches were Mode I cracks. The propagation of branched Mode I cracks in the initial Mode II damaged zone was faster than in their own Mode I zone created afterwards. The two dominantly branched cracks shielded the other small cracks appeared during the initiation of branching.

Issue Section:
Technical Papers
Topics:
Fatigue, Fatigue cracks, Finite element methods, Fracture (Materials), Stainless steel, Stress
1.
Akid, R., and Miller, K. J., 1991, “Short Fatigue Crack Growth Behaviour of A Low Carbon Steel Under Corrosion Fatigue Conditions,” Fatigue Fract. Engng Mater. Struct., pp. 637–649.
2.
Aliabadi, M. H., and Rooke, D. P., 1991, Numerical Fracture Mechanics, Kluwer Academic Publishers, London.
3.
Li
R.
, and
Chudnovsky
A.
,
1994
, “
Energy Release Rate of Crack Kinking With An Anisotropic Inclusion
,”
Int. J. Fract.
,
65
,
R3–R10
R3–R10
.
4.
Liu
H. W.
,
1985
, “
Shear Fatigue Crack Growth: A Literature Survey
,”
Fatigue Fract. Engng Mater. Struct.
, Vol.
8
, No.
4
, pp.
295
–
313
.
5.
Meguid
S. A.
,
Gaultier
P. E.
, and
Gong
S. X.
,
1991
, “
A Comparison Between Analytical and Finite Element Analysis of Main Crack-Microcrack Interaction
,”
Engng Fract. Mech.
, Vol.
38
, No.
6
, pp.
451
–
465
.
6.
Montagut
E.
, and
Kachanov
M.
,
1988
, “
On Modelling A Micraocracked Zone By “Weakened” Elastic Material and on Statistical Aspects of Crack-Microcrack Interactions
,”
Int. J. Fract.
, Vol.
37
, pp.
R55–R62
R55–R62
.
7.
Nayeb-Hashem
H.
, and
Taslim
M. E.
,
1987
, “
Effects of the Transient Mode II on the Steady State Crack Growth in Mode I
,”
Engng Fract. Mech.
, Vol.
26
, No.
6
, pp.
789
–
807
.
8.
Qian, 1995, “On Mixed-Mode Fatigue Crack Propagation And Dislocation Emission from A Mode I Crack,” Ph.D thesis, Nanjing Institute of Chemical Technology, P. R. China.
9.
Qian, C. F., Wang, M. O., Wu, B. J., Dai, S. H., and Li, J. C. M., “Mixed-Mode Fatigue Crack Growth in Stainless Steels Under Biaxial Loading,” Preceeding paper.
10.
Smith
E.
,
1993
, “
When Can We Apply LEFM Principles to Elastic Softening Materials
,”
Int. J. Fract.
,
64
, pp.
285
–
298
.
11.
Suresh, S., 1992, Fatigue of Materials, University Press, Cambridge, U.K.
12.
Wang, M. O., Hu, R. H., Zhang, C. J., and Dai, S. H., 1992, “An Experimental Investication on the Fatigue Crack Growth in Mode II Condition,” Proceedings, 7th Int. Conf. Pressure Vessel Technol., Germany, Vol. 2, pp. 1413–1427.
13.
Yuuki
R.
,
Akita
K.
, and
Kishi
N.
,
1989
, “
The Effect of Biaxial Stress State and Changes of State on Fatigue Crack Growth Behavior
,”
Fatigue Fract. Engng Mater. Struct.
, Vol.
12
, No.
2
, pp.
93
–
103
.
14.
Zhou
J.
,
Zhong
J.
,
Feng
Z.
, and
Li
N.
,
1993
, “
Growth Behaviour of Small Fatigue Cracks
,”
Int. J. Fatigue
15
, No.
2
, pp.
141
–
144
.
15.
Zuidema
J.
,
1991
, “
Explanation of the Observed Decrease in Fatigue Crack Growth Rate in Al 2024 Under Constant-ΔK Loading Using Crack Growth Resistance Models
,”
Int. J. Fatigue
13
, No.
1
, pp.
73
–
78
.
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