Hostname: page-component-cd9895bd7-7cvxr Total loading time: 0 Render date: 2024-12-26T17:37:44.915Z Has data issue: false hasContentIssue false
  • English
  • Français

EndoFEM Intergrated Methodology of Fatique Crack Propagation With Overloaded Delay Retardation

Published online by Cambridge University Press:  05 May 2011

C. F. Lee
C. F. Lee*
Affiliation:
Department of Engineering Science, National Cheng Kung University, Tainan, Taiwan 70101, R.O.C.
*
* Professor
Get access

Abstract

In this paper, EndoFEM integrated methodology developed for fatigue crack growth under constant amplitude load, was extended successfully to investigate the Kumar's experimental observations, especially in the increasing severity of delayed retardation due to increasing overload ratio. This phenomenon was accompanied with an increasing max. crack closure load (Pcl) within 0.5mm crack extension after overload, and then followed by a longer recovery stage with lower fatigue crack propagation (FCP) rate.

In the methodology, the EndoFEM with rc controlled node-released strategy was employed to produce a 2mm fatigue crack length from 6% prestrained SEN specimen. To simulate the delayed retardation of overload with/without instant crack extension, five strategies of nodal release were proposed, and then the CMOD method was employed to determine Pcl. The resulting variations of Pcl during crack extension had the same tendency as those of experimental findings. These results allowed one to propose a quadratic relationship between Pcl and Kmax under a fixed overload ratio. As a consequence, a conventional formula of crack closure model could be preserved with a modified coefficient, i.e., da/dN = C(UΔK)m. The formula proposed could predict both the a vs. N crack growth data and the da/dN vs. ΔK data under fixed overload ratios quite well.

Keywords

EndoFEMOverloaded delay retardationCrack closure loadNode-released methodFatigue crack propagation (FCP)
Type
Articles
Information
Journal of Mechanics , Volume 19 , Issue 2 , June 2003 , pp. 327 - 335
Copyright
Copyright © The Society of Theoretical and Applied Mechanics, R.O.C. 2003

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

1Geary, W., “A Review of Some Aspects of Fatigue Crack Growth under Variable Amplitude Loading,” International Journal of Fatigue, pp. 337–386 (1992).Google Scholar
2Von Euw, E. J. F., Hertzberg, R. W. and Roberts, R., “Delay Effects in Fatigue Crack Propagation,” ASTM STP513, pp. 181–186 (1972).Google Scholar
3Suresh, S., Fatigue of Meterials, 2nd ed., Cambridge Univ. Press (1998).CrossRefGoogle Scholar
4Bannantine, J. A., Comer, J. J. and Handrock, J. L., Foundamentals of Metal Fatigue Analysis, Prentice-Hall, Inc., pp. 201–206 (1990).Google Scholar
5Shin, C. S. and Hsu, S. H., “A Comparison of Five Different Methods for Crack Closure Measurement During Overload Retardation of Fatigue Crack Growth,” The Chinese J. Mech., 8, pp. 365–376 (1992).Google Scholar
6Dexter, R. J., Jr.Hudak, S. J. and Davidson, D. L., “Modelling and Measurement of Crack Closure and Crack Growth Following Overloads and Underloads,” Eng. Fract. Mech., 33, pp. 885–870 (1989).Google Scholar
7Lee, C. F. and Hsiao, L. T., “EndoFEM Crack Closure Analysis of Al 2024-T3 CCT specimen under All Tension Fatigue Loading,” The Chinese J. Mech., 16, pp. 203–215 (2000).Google Scholar
8Lee, C. F. and Hsiao, L. T., “EndoFEM Integraed Methodology for Fatigue Crack Growth,” The Chinese J. Mech., 18, pp. 89–94 (2002).Google Scholar
9Kumar, R. and Garg, S. B. L., “Effect of Yield Strength and Single Tensile Overload Cycles on Effective Stress Intensity Range Ratio in Al6061-T6 Alloy,” Engineering Fracture Mechanics, 34, pp. 403–412 (1989).Google Scholar
10Lee, C. F., “Recent Finite Element Application of the Incremental Endochronic Plasticity,” Int. J. Plasticity, 11, pp. 843–865 (1995).CrossRefGoogle Scholar
11Kyriakides, S. and Shaw, P. K., “Inelatic Buckling of Tubes under Cyclic Bending,” J. Pressure Vessel Tech., 109, pp. 169–178 (1987).Google Scholar
12Lee, C. F. and Lee, K. L., “EndoFEM Studies in the Mode I Stable Crack Growth of Fatigue Precracked CT Specimen,” The Chinese J. Mech., 15, pp. 157–167 (1999).Google Scholar