Consequences of acoustic emission on crack speed and roughness exponent in brittle dynamic fracture

Parisi, Andrea (2007) Consequences of acoustic emission on crack speed and roughness exponent in brittle dynamic fracture. In: Earthquakes and Acoustic Emission. CRC Press, pp. 89-94. ISBN 9870415444026

Full text not available from this repository.

Abstract

We show by computer simulations that acoustic emission from the crack tip strongly reduces the delivery of fracture work, due to the coupling between the crack speed and the acoustic branches in dispersive media. The direct consequence is a selection criterion for the terminal crack speed which, for planar cracks, produces results corresponding to those found in experiments on highly anisotropic materials. In case of isotropic material with cracks of unrestricted geometry, the drop in the crack speed with respect to the planar case is connected to a mechanism of attempted branching, which is also responsible for the logarithmic roughness of the final fracture for marginal loadings. Higher loadings lead to a well defined roughness exponent of ζ ~ 0.45 compatible with that measured experimentally at short length scales, and in our simulations clearly connected with the generation of macroscopic branches.

Item Type:
Contribution in Book/Report/Proceedings
ID Code:
125348
Deposited By:
Deposited On:
22 May 2018 12:10
Refereed?:
Yes
Published?:
Published
Last Modified:
15 Sep 2020 06:04