This paper presents a closure model for predicting the growth behavior of short cracks in the presence of large-scale yielding and residual compressive stresses, representative of structures that have been shot-peened. The plasticity-induced crack closure model developed by Newman is first extended by using the cyclic crack-tip opening displacement as the correlating parameter for fatigue crack growth rates. This new approach also enables a better characterization of the effect of large-scale yielding on short crack growth. The effect of residual stress on crack closure is then analyzed by adding to the loading spectrum an equivalent stress, which varies with the applied load level and the crack size. It is shown that predictions of the extended closure model are within a factor of two of the experimental results of etched specimens tested under spectrum loading, highlighting the capability of the predictive model along with some important issues for future research in this area.

Issue Section:
Technical Papers
Keywords:
fatigue cracks, crack-edge stress field analysis, modelling, internal stresses, yield stress, plasticity, surface hardening
Topics:
Fracture (Materials), Stress, Fatigue cracks, Plasticity
1.
Sharp
,
P. K.
,
Clayton
,
J. Q.
, and
Clark
,
G.
,
1994
, “
The Fatigue Resistance of Peened 7050-T7451 Aluminum Alloy-Repair Re-Treatment of a Component Surface
,”
Fatigue and Fracture of Engineering Materials and Technology
,
17
, pp.
243
–
252
.
2.
De los Rios, E. R., Trull, M., and Levers, A., 2000, “Extending the Fatigue Life of Aerospace Materials by Surface Engineering,” Proceedings of 13th European Conference on Fracture.
3.
Zhuang
,
W. Z.
, and
Halford
,
G. R.
,
2001
, “
Investigation of Residual Stress Relaxation Under Cyclic Load
,”
Int. J. Fatigue
,
23
, pp.
31
–
37
.
4.
Clark, G., and Clayton, J. Q., 1991, “Effectiveness of Peening Treatments in Improving Fatigue Resistance of 7050 Aluminum Alloy Under Constant Amplitude and Spectrum Loading,” Proc. Australian Surface Engineering Conference, Adelaide, Australia.
5.
Molent, L., Ogden, R., and Pell, R., 2000 “F/A-18 FS488 Bulkhead Fatigue Coupon Test Program,” DSTO-TR-0914, Aeronautical and Maritime Research Laboratory, Melbourne, Australia.
6.
Barter, S., and Price, J., 2000, “Effect of Surface Preparation Treatments on Fatigue Life of 7050-Aluminum Alloy,” Proceedings of Structural Integrity and Fracture 2000, Australian Fracture Group, Australia, pp 140–153.
7.
Hu, W., Wang, C. H., and Barter, S., 1999, “Analysis of Cyclic Mean Stress Relaxation and Strain Ratchetting Behaviour of Aluminum 7050,” DSTO-RR-0153, Aeronautical and Maritime Research Laboratory, Melbourne, Australia.
8.
Newman, J. C. Jr., 1992, “FASTRAN-II: a Fatigue Crack Growth Structural Analysis Program,” NASA Technical Memorandum 104159, Langley Research Center, Hampton, VA.
9.
Newman
, Jr.,
J. C.
,
1996
, “
Application of a Closure Model to Predict Crack Growth in Three Engine Disc Materials
,”
Int. J. Fract.
,
80
, pp.
193
–
218
.
10.
Wang
,
C. H.
, and
Hutchinson
,
J. W.
,
2000
, “
Interactions of Fatigue Cracks With Elastic Obstacles
,”
Int. J. Fract.
,
109
, pp.
263
–
283
.
11.
Laird, C., 1967, “The Influence of Metallurgical Structure on the Mechanisms of Fatigue Crack Propagation,” Fatigue Crack Propagation, ASTM STP 415, American Society of Testing and Materials, Philadelphia, pp. 131–168.
12.
Guo
,
W.
,
Wang
,
C. H.
, and
Rose
,
L. R. F.
,
1999
, “
On the Influence of Cross Sectional Thickness on Fatigue Crack Growth
,”
Fatigue and Fracture of Engineering Materials and Technology
,
22
, pp.
437
–
444
.
13.
Wang
,
C. H.
, and
Rose
,
L. R. F.
,
1999
, “
Crack-Tip Plastic Blunting Under Gross-Section Yielding and Implications for Short Crack Growth
,”
Fatigue and Fracture of Engineering Materials and Structures
,
22
, pp.
761
–
773
.
14.
Rose
,
L. R. F.
, and
Wang
,
C. H.
,
2001
, “
Self-Similar Analysis of Plasticity-Induced Closure of Small Fatigue Cracks
,”
J. Mech. Phys. Solids
,
49
, pp.
401
–
429
.
15.
Fuhring
,
H.
, and
Seeger
,
T.
,
1979
, “
Dugdale Crack Closure Analysis of Fatigue Cracks Under Constant Amplitude Loading
,”
Eng. Fract. Mech.
,
11
, pp.
99
–
122
.
16.
Wang
,
C. H.
,
Rose
,
L. R. F.
, and
Newman
, Jr.,
J. C.
,
2002
, “
Fatigue Crack Closure Under Large-Scale Yielding Conditions
,”
Fatigue and Fracture of Engineering Materials and Structures
,
25
, pp.
127
–
140
.
17.
Newman
, Jr.,
J. C.
,
1998
, “
The Merging of Fatigue and Fracture Mechanics Concepts: a Historical Perspective
,”
Prog. Aerosp. Sci.
,
34
, pp.
347
–
390
.
18.
Newman, J. C. Jr., 1992, “Fracture Mechanics Parameters for Small Fatigue Cracks, Small-crack Test Methods,” ASTM STP 1149, J. Larsen and J. E. Allison, eds., American Society for Testing and Materials, Philadelphia, pp. 9–33.
19.
Tada, H, Paris, P. C., and Irwin, G. R., 2000, The Stress Analysis of Cracks Handbook, The American Society of Mechanical Engineers, New York.
20.
Wang
,
G. S.
,
1993
, “
The Plasticity Aspect of Fatigue Crack Growth
,”
Eng. Fract. Mech.
,
46
, pp.
909
–
930
.
21.
Wang
,
G. S.
,
1999
, “
A Strip Yield Analysis of Fatigue Crack Growth in the Residual Stress Field
,”
Int. J. Fract.
,
96
, pp.
247
–
277
.
22.
Wang
,
G. S.
,
1999
, “
Post Yield Fatigue Crack Growth Analyses
,”
Eng. Fract. Mech.
,
64
, pp.
1
–
21
.
Copyright © 2003
 by ASME
You do not currently have access to this content.