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Continuum Mechanics-Discrete Defect Modeling and Bubble Raft Simulation of Cracked Specimen Response in Nanoscale Geometries

Published online by Cambridge University Press:  11 February 2011

Michael J. Starr ,
Walter J. Drugan ,
Maria d. C. Lopez-Garcia  and
Donald S. Stone
Michael J. Starr
Affiliation:
Structural Dynamics Research Department, Sandia National Laboratories, Albuquerque, NM 87185–0847, U.S.A.
Walter J. Drugan
Affiliation:
Mechanics and Materials Program, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.
Maria d. C. Lopez-Garcia
Affiliation:
Department of Chemical Engineering, University of Puerto Rico-Mayaguez, Mayaguez, P.R.
Donald S. Stone
Affiliation:
Mechanics and Materials Program, University of Wisconsin-Madison, Madison, WI 53706, U.S.A.
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Abstract

In a continuation of prior work, a new group of Bragg bubble model experiments have been performed to explore the effects of nanoscale crack size and nanoscale structural geometry on atomically-sharp crack tip dislocation emission behavior. The experiments have been designed to correspond to the theoretical limits that bound the expected crack tip response. Continuum elasticity analyses of these situations have also been carried out, in which the leading-order terms in the Williams expansion (the K and T terms) are determined, and the predictions of these continuum analyses coupled with discrete dislocation theory are compared with the experimental results. The experiments exhibit fascinating changes in crack tip dislocation emission direction with changing crack and structural size, crack location and loading conditions, as well as substantial changes in the magnitude of the resolved shear stress that drives dislocation emission. These changes are predicted well by the continuum elasticity-discrete dislocation model down to extremely small dimensions, on the order of a few atomic spacings. Preliminary experiments were performed with layered and two-atom basis rafts to establish crucial comparisons between theory and experiment that validate the applicability of continuum elasticity theory to make predictions directly related to nanoscale fracture behavior.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 740: Symposium I – Nanomaterials for Structural Applications , 2002 , I8.3
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Rice, J. R. and Thomson, R., Phil. Mag. 29, 73 (1974).Google Scholar
2. Bragg, W. L. and Nye, J. F., Proc. Roy. Soc. Lond. A, 190, 474 (1947).Google Scholar
3. Lomer, W. M., Proc. Roy. Soc. Lond. A, 196, 182 (1949).Google Scholar
4. Shi, L. T. and Argon, A. S., Phil. Mag. A, 46 (2), 255 (1982).Google Scholar
5. Argon, A. S., and Shi, L. T., Phil. Mag. A, 46 (2), 275 (1982).Google Scholar
6. McClintock, F. A. and O'Day, W. R., Proc. Int. Conf. Frac. 1, 75 (1965).Google Scholar
7. Gouldstone, A., Van Vliet, K. J., and Suresh, S., Nature 411, 656 (2001).Google Scholar
8. Starr, M. J. and Drugan, W. J. (Proc. Soc. Exp. Mech., Milwaukee, WI, 2002) pp. 145–148.Google Scholar
9. Erdogan, F. and Gupta, G., Int. J. Solids Structures 7, 39 (1971).Google Scholar
10. Starr, M. J. and Drugan, W. J., (manuscript in preparation for publication).Google Scholar
11. Beltz, G. E. and Fischer, L. L. in Multiscale Deformation and Fracture in Materials and Structures, edited by Chuang, T.-J. and Rudnicki, J. W., (2000), pp. 237–242.Google Scholar
12. Geselbracht, M. J., Ellis, A. B., Penn, R. L., Lisensky, G. C., and Stone, D. S., J. Chem. Ed. 71, 254 (1994).Google Scholar
13. Starr, M. J., PhD. Thesis, University of Wisconsin-Madison, 2002.Google Scholar