This paper reviews the capabilities of a plasticity-induced crack-closure model and life-prediction code, FASTRAN, to predict fatigue lives of metallic materials using small-crack theory. Crack-tip constraint factors, to account for three-dimensional state-of-stress effects, were selected to correlate large-crack growth rate data as a function of the effective-stress-intensity factor range (ΔKeff) under constant-amplitude loading. Some modifications to the ΔKeff-rate relations were needed in the near-threshold regime to fit small-crack growth rate behavior and endurance limits. The model was then used to calculate small- and large-crack growth rates, and to predict total fatigue lives, for notched specimens made of several aluminum alloys and a titanium alloy under constant-amplitude and spectrum loading. Fatigue lives were calculated using the crack-growth relations and microstructural features like those that initiated cracks for the aluminum alloys. An equivalent-initial-flaw-size concept was used to bound the fatigue lives for the titanium alloy. Results from the tests and analyses agreed well.

Issue Section:
Technical Papers
Topics:
Fatigue life, Fracture (Materials), Fatigue, Aluminum alloys, Stress, Titanium alloys, Endurance limit, Plasticity
1.
Blom, A. F., Wang, G. S., and Chermahini, R. G., 1990, “Comparison of Crack Closure Results Obtained by 3-D Elastic-Plastic FEM and Modified Dugdale Model,” Proceedings 1st International Conference on Computer Aided Assessment and Control of Localized Damage, Portsmouth, England, pp. 57–68.
2.
deJonge, J. B., Schutz, D., Lowak, H., and Schijve, J., 1973, “A Standardized Load Sequence for Flight Simulation Tests on Transport Aircraft Wing Structures (TWIST),” NLR TR-73029 U, Nationaal Lucht-en Ruimtevaart-laborium, Netherlands.
3.
Dugdale
D. S.
,
1960
, “
Yielding of Steel Sheets Containing Slits
,”
Journal of Mechanics and Physics of Solids
, Vol.
8
, Vol. 2, pp.
100
–
104
.
4.
Edwards, P. R., and Newman, J. C., Jr., eds., 1990, “Short-Crack Growth Behaviour in Various Aircraft Materials,” AGARD Report No. 767.
5.
Elber
W.
,
1971
, “
The Significance of Fatigue Crack Closure
,”
Damage Tolerance in Aircraft Structures
, ASTM STP
486
, pp.
230
–
242
.
6.
El Haddad
M. H.
,
Dowling
N. E.
,
Topper
T. H.
, and
Smith
K. N.
,
1980
, “
J Integral Application for Short Fatigue Cracks at Notches
,”
International Journal of Fracture
, Vol.
16
, No.
1
, pp.
15
–
30
.
7.
Huck, M., Schutz, W., Fischer, R., and Kobler, H. G., 1976, “A Standard Random Load Sequence of Gaussian Type Recommended for General Application in Fatigue Testing,” IABG Report No. TF-570 or LBF Report No. 2909, Germany.
8.
Lowak, H., deJonge, J. B., Franz, J., and Schutz, D., 1979, “Mini-TWIST—A Shortened Version of TWIST,” LBF Report No. TB-146, Laboratorium fur Betriebsfestigkeit, Germany.
9.
Minakawa, K., and McEvily, A. J., 1981, “On Near-Threshold Fatigue Crack Growth in Steels and Aluminum Alloys,” Proceedings of the International Conference on Fatigue Thresholds, Vol. 2, pp. 373–390.
10.
Mom, A. J. A., and Raizenne, M. D., eds., 1988, “AGARD Engine Disc Cooperative Test Programme,” AGARD Report No. 766.
11.
Newman, J. C., Jr., 1981, “A Crack-Closure Model for Predicting Fatigue Crack Growth under Aircraft Spectrum Loading,” Methods and Models for Predicting Fatigue Crack Growth under Random Loading, J. B. Chang and C. M. Hudson, eds., ASTM STP 748, pp. 53–84.
12.
Newman, J. C., Jr., 1983, “A Nonlinear Fracture Mechanics Approach to the Growth of Small Cracks,” “Behaviour of Short Cracks in Airframe Components,” H. Zocher, ed., AGARD CP-328, pp. 6.1–6.26.
13.
Newman
J. C.
,
1984
, “
A Crack-Opening Stress Equation for Fatigue Crack Growth
,”
International Journal of Fracture
, Vol.
24
,
R131–R135
R131–R135
.
14.
Newman, J. C., Swain, M. H., and Phillips, E. P., 1986, “An Assessment of the Small-Crack Effect for 2024-T3,” Small Fatigue Cracks, Ritchie, R. O., and Lankford, J., eds., pp. 427–452.
15.
Newman, J. C., Jr., and Edwards, P. R., 1988, “Short-Crack Growth Behaviour in an Aluminum Alloy—AGARD Cooperative Test Programme,” AGARD R-732.
16.
Newman, J. C., Jr., 1992a, “Fracture Mechanics Parameters for Small Fatigue Cracks,” Small Crack Test Methods, ASTM STP 1149, J. Allison and J. Larsen, eds., pp. 6–28.
17.
Newman, J. C., Jr., 1992b, “FASTRAN II–A Fatigue Crack Growth Structural Analysis Program,” NASA TM 104159.
18.
Newman, J. C., Jr., Wu, X. R., Venneri, S. L., and Li, C. G., 1994, “Small-Crack Effects in High-Strength Aluminum Alloys–A NASA/CAE Cooperative Program,” NASA Reference Publication 1309.
19.
Nisitani
H.
, and
Takao
K. I.
,
1981
, “
Significance of Initiation, Propagation and Closure of Microcracks in High Cycle Fatigue of Ductile Materials
,”
Engineering Fracture Mechanics
, Vol.
15
, No.
3
, pp.
455
–
456
.
20.
Pearson
S.
,
1975
, “
Initiation of Fatigue Cracks in Commercial Aluminum Alloys and the Subsequent Propagation of Very Short Cracks
,”
Engineering Fracture Mechanics
, Vol.
7
, No.
2
, pp.
235
–
247
.
21.
Powell, B. E., and Henderson, I., 1983, “The Conjoint Action of High and Low Cycle Fatigue,” AFWAL-TR-83–4119.
22.
Raizenne, M. D., 1990, “AGARD SMP Sub-Committee 33 Engine Disc Test Programme Fatigue Crack Growth Rate Data and Modeling Cases for Ti-6Al-4V, IMI-685 and Ti-17,” LTR-ST-1785, National Research Council, Canada.
23.
Ritchie, R. O., and Lankford, J., eds., 1986a, Small Fatigue Cracks. The Metallurgical Society, Inc., Warrendale, PA.
24.
Rudd, J. L., Yang, J. N., Manning, S. D., and Garver, W. R., 1982, “Durability Design Requirements and Analysis for Metallic Airframes,” Design of Fatigue and Fracture Resistant Structures, ASTM STP 761, P. R. Abelkis and C. M. Hudson, eds., pp. 133–151.
25.
Schijve
J.
,
1967
, “
Significance of Fatigue Cracks in Micro-Range and Macro-Range
,”
Fatigue Crack Propagation
, ASTM STP
415
, pp.
415
–
459
.
26.
van Dijk, G. M., and deJonge, J. B., 1975, “Introduction to a Fighter Loading Standard for Fatigue Evaluation—FALSTAFF,” NLR MP 75017 U, Nationaal Lucht-en Ruimtevaartlaborium.
27.
Wanhill, R. J. H., and Looije, C. E. W., 1993, “Fractographic and Microstructural Analysis of Fatigue Crack Growth in Ti-6Al-4V Fan Disc Forgings,” AGARD Engine Disc Cooperative Test Programme, T. Pardessus, E. Jany, and M. D. Raizenne, eds., AGARD Report 766 (addendum).
28.
Zocher, H., ed., 1983, “Behaviour of Short Cracks in Airframe Components,” AGARD CP-328.
This content is only available via PDF.
Copyright © 1995
 by The American Society of Mechanical Engineers
You do not currently have access to this content.