Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-23T17:09:56.557Z Has data issue: false hasContentIssue false
  • English
  • Français

EndoFEM Crack Closure Analysis of AL2024-T3 CCT Specimen Under All Tension Fatigue Loading

Published online by Cambridge University Press:  05 May 2011

C. F. Lee  and
L. T. Hsiao
C. F. Lee*
Affiliation:
Department of Engineering Science, National Cheng-Kung University, Tainan, Taiwan 70101, R.O.C.
L. T. Hsiao*
Affiliation:
Department of Engineering Science, National Cheng-Kung University, Tainan, Taiwan 70101, R.O.C.
*
*Professor
**Director of Manufacture Div., Hsin-Ho Machinery Co.
Get access

Abstract

The endochronic cyclic plasticity with finite element analysis (EndoFEM) is employed to simulate plasticity-induced crack closure phenomenon of Al 2024-T3 CCT specimens under maximum cyclic stress of 80MPa and 0.1 stress ratio (R). Various fatigue crack lengths are generated by a rc dominated-node-released strategy. The suitability of element-mesh planning around crack tip is supported by the real simulations in the decreasing tendencies of crack opening load (Pop) with increased distance behind the crack tip, and the enough elements to reflect the reversed plastic responses at minimum load.

EndoFEM results of vertical stress ahead of the crack tip show a typical distribution of small scale yield (SSY) in the realm of fracture mechanics; and Pop/Pmax ratio determined at 1mm behind crack tip is kept constant i.e. Kmax-independent. In these cases, fatigue parameters based on either the far field loading parameter ΔK, the effective ΔK (ΔKeff) with crack closure effect, or the mechanical responses ahead of crack tip (e.g. stress parameter, reversed (plastic) strain at 1mm) are all equivalent and are linearly correlated with the stage II fatigue crack growth (FCP) rate. However, for longer crack length with the ligament bending effect or shorter crack length with the starter notch effect, the Pop/Pmax ratio decreases and changes the SSY stress distribution. This result reduces the usefulness of the above fatigue parameters. As a consequence, a nonlinear correlation of FCP rates with ΔK or ΔKeff are purely empirical. The Kmax-dependent ΔKeff must be considered in the correlation as suggested by the present study of EndoFEM.

Keywords

EndoFEMplasticity-induced crack closurerc dominated-node-released strategyAl 2024-T3 CCT specimensda/dN of FCP
Type
Articles
Information
Journal of Mechanics , Volume 16 , Issue 4 , December 2000 , pp. 203 - 215
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1Elber, W., “Fatigue Crack Closure Under Cyclic Growth,” Engineering Fracture Mechanics, 2, pp. 37–45 (1970).Google Scholar
2Shih, T. T. and Wei, R. P., “A Study of Crack Closure in Fatigue,” Engineering Fracture Mechanics, 6, pp. 19–32 (1974).Google Scholar
3Schijve, J., “Some Formulas for The Crack Opening Stress Level,” Engineering Fracture Mechanics, 14, pp. 461–465 (1981).CrossRefGoogle Scholar
4Abdel Mageed, A. M., Pandey, R. K. and Chinadurai, R., “Effect of Measurement Location and Fatigue-Loading Parameters on Crack Closure Behaviour,” Materials Science and Engineering, A150, pp. 43–50 (1992).CrossRefGoogle Scholar
5Budiansky, B. and Hutchinson, J. W., “Analysis of Closure in Fatigue Crack Growth,” J. Applied Mechanics, ASME, 45, pp. 267–276 (1978).CrossRefGoogle Scholar
6Newman, J. C. Jr., “A Finite Element Analysis of Fatigue Crack Closure,” ASTM STP 590, pp. 281–301 (1976).Google Scholar
7Newman, J. C. Jr., “A Crack Opening Stress Equation for Fatigue Crack Growth,” Int. J. Fracture, 24, pp. 131–135 (1984).CrossRefGoogle Scholar
8McClung, R. C. and Sehitoglu, H., “On The Finite Element Analysis of Fatigue Crack Closure -1: Basic Modeling Issues,” Engineering Fracture Mechanics, 33, pp. 237–252 (1989).CrossRefGoogle Scholar
9McClung, R. C., “The Influence of Applied Stress, Crack Length, and Stress Intensity Factor on Crack Closure,” Metallurgical Transaction A, 22A, pp. 1559–1571 (1991).CrossRefGoogle Scholar
10Ellyin, F. and Wu, J., “Elastic-Plastic Analysis of A Stationary Crack Under Cyclic Loading and Effect of Overload,” Int. J. Fracture, 56, pp. 189–208 (1992).Google Scholar
11Valanis, K. C., “Fundamental Consequences of a New Intrinsic Time Measure: Plasticity As a Limit of The Endochronic Theory,” Archives of Mechanics, 32, pp. 171–191 (1980).Google Scholar
12Lee, C. F., “Numerical Method of the Incremental Endochronic Plasticity,” Chinese J. Mechanics, 8, pp. 377–396 (1992).Google Scholar
13Lee, C. F., “Recent Finite Element Applications of The Incremental Endochronic Plasticity,” Int. J. Plasticity, 11, pp. 843–865 (1995).Google Scholar
14Fuchs, H. O. and, Stephens, R. I., Metal Fatigue in Engineering. Wiley-Interscience, New York, pp. 298–299 (1980).Google Scholar
15Valanis, K. C. and Lee, C. F., “Endochronic Theory of Cyclic Plasticity With Applications,” J. Applied Mechanics, 51, pp, 367–374 (1984).CrossRefGoogle Scholar
16Lee, C. F., “A Systematic Method of Determining Material Functions in the Endochronic Plasticity,” J. the Chinese Society of Mechanical Engineers, 8, pp. 419–430 (1987).Google Scholar
17Valanis, K. C. and Lee, C. F., “Some Recent Developments in The Endochronic Theory With Application to Cyclic Histories,” in NASA Symposium on Nonlinear Constitutive Relations for High Temperature Applications. Univ. Akron, Akron, Ohio U.S.A., pp. 191–216, May (1982).Google Scholar
18Watanabe, O. and Atluri, S. N., “Internal Time, General Internal Variable, and Multi-Yield-Surface Theories of Plasticity and Creep: A Unification of Concepts,” Int. J. Plasticity, 2, pp. 37–57 (1986).Google Scholar
19Chaboche, J. L., “On Some Modifications of Kinematic Hardening to Improve The Description of Ratchetting Effects,” Int. J. Plasticity, 7, pp. 661–678 (1991).Google Scholar
20Ohno, N. and Wang, J. D., “Kinematic Hardening Rules With Critical State of Dynamic Recovery, PartI: Formulation and Basic Features for Ratchetting Behavior; Part II: Application to Experiments of Ratchetting Behavior,” Int. J. Plasticity, 9, pp. 375–403 (1993).Google Scholar
21Hsiao, L. T. and Lee, C. F., “EndoFEM Node-Released Strategies on The Simulations of Fatigue Crack Closure Phenomena,” Chinese J. Mechanics, 14, pp. 57–66 (1998).Google Scholar
22Elber, W., “The Significance of Fatigue Crack Closure,” Damage Tolerance in Aircraft Structures, ASTM STP 486, pp. 230–242 (1971).Google Scholar
23Dowling, N. E. and Begley, J. A., “Fatigue Crack Growth During Gross Plasticity and the J-Integral,” ASTM STP 590, pp. 82–103 (1976).Google Scholar
24Shin, C. S. and Li, R. Z., “Fatigue Crack Propagation in the Elastic-Plastic Regime in a Low Alloy Structural Steel,” J. Chinese Inst. Eng. 22, pp. 275–284 (1999).Google Scholar
25Dover, W. D., “Fatigue Crack Growth Under COD Cycling,” Eng. Fracture Mech., 5, pp. 11–21 (1973).Google Scholar
26Ming, L. Du. and Chiang, Fu-Pen, “Crack Tip Plasticity as a Parameter for Fatigue Crack Growth,” Proceedings of Plasticity '97: The Sixth Int. Symp. on Plasticity and Its Current Applications, ed. Khan, A.S., pp. 347–348 (1997).Google Scholar
27ASTM. 1990 Annual Book of ASTM Standards, 03.01, ASTM No. E647, “Measurement of Fatigue Crack Growth Rates,” Philadelphia, Pa. U.S.A.Google Scholar
28Hiroshi, M. and Schijve, J.Fatigue Crack Growth in Aluminium Alloy Sheet Material Under Constant-Amplitude and Simplified Flight-Simulation Loading. Report LR-381, Delft University of Technology, Delft, The Netherlands (1983).Google Scholar