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Experimental Analysis of Deformation Induced Microstructure Near a Crack Tip in a Hardened Copper Crystal

Published online by Cambridge University Press:  15 February 2011

A.-F. Bastawros
Affiliation:
Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA02138
K.-S. Kim
Affiliation:
Division of Engineering, Brown University, Providence, RI 02912
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Abstract

The incremental in-plane Green-Lagrange strain tensor was measured near a stationary crack tip in a cyclically work-hardened copper single crystal. Measurements were made on the surface of a four-point bend specimen, using a finite-deformation laser moiré interferometer. The measurement showed the existence of a narrow asymptotic field beyond a distance of 300 μm from the crack tip. The inner boundary of the asymptotic zone was almost fixed at a characteristic distance ahead of the crack tip. This length scale is thought to arise from a microstructural evolution near the crack tip. The inhomogeneous hardening due to glide-band clustering and patchy slip in a small volume near the crack tip triggered such an evolution. The outer boundary of the asymptotic zone radially grew with the increasing load. The deformation field was found to be very sensitive to additional mode II loading.

Type
Research Article
Copyright
Copyright © Materials Research Society 1999

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References

1. Rice, J.R., J. Appl. Mech. 35, 379386 (1968); Mech. Mater. 6, 317–335 (1987).Google Scholar
2. Saeedvafa, M. and Rice, J.R., J. Mech. Phys. Solids, 37, 673691 (1989).Google Scholar
3. Cuitiño, A.M. and Ortiz, M., Modeling Simul. Mater. Sci. Engng., 1, 225263 (1992);Google Scholar
J. Mech. Phys. Solids, 44, 863904 (1996).Google Scholar
4. Rice, J.R., Hawk, D.E., Asaro, R.J., Int. J. Fracture, 42, 301 (1990).Google Scholar
5. Mohan, R., Ortiz, M., Shih, C.F., J. Mech. Phys. Solids 40, 315 (1992); 40, 1907 (1992).Google Scholar
6. Saeedvafa, M., Mech. Mater. 19, 7388 (1994).Google Scholar
7. Nikolic, R., PhD Thesis, Harvard University, 1989.Google Scholar
8. Cho, J.W., and Yu, J., Phil. Mag. Letters, 64, 175182 (1991).Google Scholar
9. Li, X.M., Chiang, F.P., Wu, J., and Duddley, M., Engng. Fracture Mech. 43, 171184 (1992).Google Scholar
10. Shield, T.W. and Kim, K.-S., Exp. Mech. 31, 126134 (1991).Google Scholar
11. Bastawros, A.-F. and Kim, K.-S., to be submitted to J. Mech. Phys. Solids (1998).Google Scholar
12. Bastawros, A.-F., PhD thesis, Brown University, 1997.Google Scholar
13. Yan, B., Hunsche, A., Neumann, P, and Laird, C., Mater. Sci. Engng. 79, 914 (1986).Google Scholar
14. Rice, J.R., Paris, P.C., and Merkle, J.G., ASTM STP 536, 231245, (1973).Google Scholar
15. O'Dowd, N.P. and Shih, C.F., J. Mech. Phys. Solids 39, 9891015 (1991); 40, 939–963 (1992).Google Scholar
16. McMeeking, R.M. and Parks, D.M., ASTM STP 668, 175194 (1979).Google Scholar
17. Shih, C.F. and German, M.D., Int. J. Fracture 17, 2743 (1981).Google Scholar
18. Hall, E. O., Proc. Phys. Soc. Lond., B, 64,747 (1951).Google Scholar
19. Petch, N.J., J. Iron Steel Inst., London, 174, 25 (1953).Google Scholar
20. Wei, Y. and Hutchinson, J., J. Mech. Phys. Solids 45, 12531273 (1997).Google Scholar