TITLE:
Numerical Crack Analysis of Blunt Rock Indenters by an Indirect Boundary Element Method
AUTHORS:
Narges Sadat Tayarani, Mohammad Fatehi Marji
KEYWORDS:
Numerical Modeling; Boundary Element Method; Rock Indentation; Linear Elastic Fracture Mechanics (LEFM)
JOURNAL NAME:
Geomaterials,
Vol.3 No.4,
October
14,
2013
ABSTRACT: Linear elastic fracture
mechanics principles are widely applied for the analysis of crack problems in
rock fracture mechanics.
Rock indentation is an important and complicated problem among rock engineering
issues. In this paper, in addition to the fracture criterion of maximum
tangential stress adjacent to crack tip, the higher order displacement discontinuity method
(which is a version of the indirect boundary element method) has been used for
modeling the crack propagation mechanism under blunt indenters. In order to
achieve more accurate results, higher order boundary elements i.e.
quadratic elements, has been used to calculate displacement discontinuities and
also to reduce the singularities of stress and displacement fields near the crack
tip, the special crack tip elements has been used to calculate the stress
intensity factors (SIF)
at the crack tips. In this modeling, the effect of crack angle on stress
intensity factors has been investigated. The numerical results of stress
intensity factors obtained from some example problems were compared to the theoretical and
experimental results cited in the literature which always show a percentage
error less than one percent. The simulated results may pave the way for
increasing the efficiency of mining and drilling by improving the design of
tools and indentation equipments.