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On The Response Of Dynamic Cracks To Increasing Overload

Published online by Cambridge University Press:  15 February 2011

P. Gumbsch*
Affiliation:
Max-Planck-Institut für Metallforschung, Seestr. 92, 70174 Stuttgart, Germany
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Abstract

One of the most interesting questions in the dynamics of brittle fracture is how a running brittle crack responds to an overload, i.e. to a mechanical energy release rate larger than that due to the increase in surface energy of the two cleavage surfaces. To address this question, dynamically running cracks in different crystal lattices are modelled atomistically under the condition of constant energy release rate. Stable crack propagation as well as the onset of crack tip instabilities are studied.

It will be shown that small overloads lead to stable crack propagation with steady state velocities which quickly reach the terminal velocity of about 0.4 of the Rayleigh wave speed upon increasing the overload. Further increasing the overload does not change the steady state velocity but significantly changes the energy dissipation process towards shock wave emission at the breaking of every single atomic bond. Eventually the perfectly brittle crack becomes unstable, which then leads to dislocation generation and to the production of cleavage steps. The onset of the instability as well as the terminal velocity are related to the non-linearity of the interatomic interaction.

Type
Research Article
Copyright
Copyright © Materials Research Society 1996

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References

[1] Fineberg, J., Gross, S. P., Marder, M., and Swinney, H. L., Phys. Rev. Letters 67, 457 (1991).Google Scholar
[2] Fineberg, J., Gross, S. P., Marder, M., and Ht. Swinney, L., Phys. Rev. B 45, 5146 (1992).Google Scholar
[3] Gross, S. P. et al., Phys. Rev. Letters Ti, 3162 (1993).Google Scholar
[4] Freund, L. B., Dylnamical Fracture Mechanics (Cambridge niversity Press, New York, 1990).Google Scholar
[5] Yoffe, E. H., Philos. Mag. 42, 739 (1951).Google Scholar
[6] Griffith, A. A., Philos. Trans. R. Soc. 221A, 163 (1921).Google Scholar
[7] Thomson, R., Htsieh, C., and Rana, V., J. Appl. Phys. 42, 3154 (1971).Google Scholar
[8] Sinclair, J. E., Phil. Mag. 31,647 (1975).Google Scholar
[9] Lawn, B., Fracture of Brittle Solids – Second Edition (University Press, Cambridge, UK, 1993).Google Scholar
[10] Marder, M. and Liu, X., Phys. Rev. Letters 71, 2417 (1993).Google Scholar
[11] Marder, M. and Gross, S., J. Mech. Phys. Solids 43, 1 (1995).Google Scholar
[12] Foiles, S. M., Baskes, M. I., and Daw, M. S., Phys. Rev. B 33, 7983 (1986).Google Scholar
[13] Gumbsch, P., J. Mat. Res. 10, 2897 (1995).Google Scholar
[14] Gumbsch, P. and Beltz, G. E., Modelling Simul. Mater. Sci. Eng. 3, 597 (1995).Google Scholar
[15] Hoagland, R. G., Daw, M. S., and Hirth, J. P., J. Mater. Res. 6, 2565 (1991).Google Scholar
[16] Finnis, M. W., Agnew, P., and Foreman, A. J. E., Phys. Rev. B 44, 567 (1991).Google Scholar
[17] Berendsen, H. J. C. et al., J. Chem. Phys. 81, 3684 (1984).Google Scholar
[18] Holian, B. L. and Ravelo, R., Phys. Rev. B 51, 11275 (1995).Google Scholar