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arXiv · 0807.4866

The Breakdown of Linear Elastic Fracture Mechanics near the Tip of a Rapid Crack

Ariel Livne·Eran Bouchbinder·Jay Fineberg
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Abstract

We present high resolution measurements of the displacement and strain fields near the tip of a dynamic (Mode I) crack. The experiments are performed on polyacrylamide gels, brittle elastomers whose fracture dynamics mirror those of typical brittle amorphous materials. Over a wide range of propagation velocities ($0.2-0.8c_s$), we compare linear elastic fracture mechanics (LEFM) to the measured near-tip fields. We find that, sufficiently near the tip, the measured stress intensity factor appears to be non-unique, the crack tip significantly deviates from its predicted parabolic form, and the strains ahead of the tip are more singular than the $r^{-1/2}$ divergence predicted by LEFM. These results show how LEFM breaks down as the crack tip is approached.

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Ariel Livne, Eran Bouchbinder, Jay Fineberg. 2008-10-07. The Breakdown of Linear Elastic Fracture Mechanics near the Tip of a Rapid Crack. https://doi.org/10.1103/physrevlett.101.264301

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