Crack Front Waves and the Dynamics of a Rapidly Moving Crack

E. Sharon1, G. Cohen2, and J. Fineberg2

1The Center for Nonlinear Dynamics, The University of Texas, Austin, Texas 78712

2The Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel

Received 19 July 2001; published 6 February 2002

Crack front waves are nonlinear localized waves that propagate along the leading edge of a crack. They are generated by both the interaction of a crack with a localized material inhomogeneity and the intrinsic formation of microbranches. Front waves are shown to transport energy, generate surface structure, and lead to localized velocity fluctuations. Their existence locally imparts inertia, which is not incorporated in current theories of fracture, to initially massless cracks. This, coupled to microbranch formation, yields both inhomogeneity and scaling behavior within the fracture surface structure.