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A Mother-Daughter Mechanism of Mode I cracks: Supersonic Crack Motion Along Interfaces of Dissimilar Materials

Published online by Cambridge University Press:  26 February 2011

Markus J. Buehler
Affiliation:
mbuehler@MIT.EDU, Massachusetts Institute of Technology, CEE, 77 Mass. Ave Room 1-272, Cambridge, MA, 02139, United States, 626 628 4087, 617 258-6775
Huajian Gao
Affiliation:
hgao@mf.mpg.de, Max Planck Institute for Metals Research, Germany
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Abstract

In this paper we summarize recent progress in applying large-scale atomistic studies of crack dynamics along interfaces of dissimilar materials. We consider two linear-elastic material strips in which atoms interact with harmonic potentials, with a different spring constant in each layer leading to a soft and a stiff strip. The two strips are bound together with a weak potential whose bonds snap early upon a critical atomic separation. An initial crack serves as initiation point for the failure. We will focus on the maximum speed of mode I loaded cracks along such a biomaterial interface. Upon nucleation of the crack, it quickly approaches a velocity a few percent larger than the Rayleigh-wave speed of the soft material. After a critical time, we observe that a secondary crack is nucleated a few atomic spacings ahead of the crack. This secondary crack propagates at the Rayleigh-wave speed of the stiff material. If the elastic mismatch is sufficiently large, the secondary crack can be faster than the longitudinal wave speed of the soft material, thus propagating supersonically. Supersonic crack motion is clearly identified by two Mach cones in the soft material. This suggests that mother-daughter mechanisms, formerly only reported in mode II cracks in homogeneous materials, play an important role in interfacial mode I crack dynamics. The studies reported in this paper exemplify the usage of large-scale atomistic simulation to investigate the physics of fracture.

Type
Research Article
Copyright
Copyright © Materials Research Society 2006

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References

1 Gao, H.J., Huang, Y., Abraham, F.F. Continuum and Atomistic Studies of Intersonic Crack Propagation, J. Mech. Physc. Solids 49, 21132132 (2001).Google Scholar
2 Buehler, M.J., Abraham, F.F., Gao, H., Hyperelasticity Governs Dynamic Fracture at a Critical Length Scale, Nature 49, 441446 (2003)Google Scholar
3 Buehler, M.J., Gao, H., Huang, Y., Continuum and Atomistic Studies of Suddenly Stopping Supersonic Cracks, Computational Materials Science 28, 385408 (2003).Google Scholar
4 Abraham, F.F., Brodbeck, D., Rudge, Instability Dynamics of Fracture: A Computer Simulation Investigation Xu, W.E., X. Phys. Rev. Lett. 73, 272275 (1994).Google Scholar
5 Rice, J.R., Sih, G.C. Plane Problems of Cracks in Dissimilar Media. Trans. of the ASME 32(2), 418423 (1965)Google Scholar
6 England, A.H. A Crack Between Dissimilar Media. J. Appl. Mech. 32, 400402 (1965)Google Scholar
7 Rice, J.R. Elastic fracture mechanics concepts for interfacial cracks. Trans. of the ASME 55(1), 98103 (1988)Google Scholar
8 Williams, M.L. The stresses around a fault or crack in dissimilar media. Bull. Seismol. Soc. America 49, 199204 (1959).Google Scholar
9 Yang, W., Suo, Z., Shih, C.F. Mechanics of dynamic debonding, Proc. Roy. Soc. Lond. A 433, 679697 (1991).Google Scholar
10 Liu, C., Lambros, J., Rosakis, A.J. Highly transient elastodynamic crack growth in a bimaterial interface: higher order asymptotic analysis and experiments. J. Mech. Phys. Solids 41, 18871954 (1993).Google Scholar
11 Lambros, J., Rosakis, A.J. Development of a dynamic decohesion criterion for subsonic fracture of the interface between two dissimilar materials. Proc. Roy. Soc. Lond. A 41, 711736 (1995)Google Scholar
12 Rosakis, A.J. Intersonic crack propagation in bimaterial systems. J. Mech. Phys. Solids 6(10), 17891813 (1998).Google Scholar
13 Rosakis, A.J. Intersonic shear cracks and fault ruptures.Adv. Phys. 51(4), 11891257 (2002).Google Scholar
14 Abraham, F.F et al. Simulating Materials Failure by using up to one billion atoms: Brittle Fracture. Proc. Nat. Acad. Sci. 99, 57885792 (2002).Google Scholar
15 Chen, S. Personal communication.Google Scholar
16 Buehler, M.J., Gao, H., Dynamical Fracture Instabilities due to Local Hyperelasticity at Crack Tips, Nature, 2006 (in press)Google Scholar