Crack propagation and coalescence in brittle materials under compression

• Two particular cases concerning crack propagation and coalescence in brittle materials have been modeled by using the rock failure process analysis code, RFPA2D, and the results have been validated by reported experimental observations. Firstly, axial compression of numerical samples containing a number of large, pre-existing flaws and a row of suitably oriented smaller flaws are simulated. It has been confirmed that under axial compression, wing-cracks nucleate at the tips of the pre-existing flaws, grow with increasing compression, and become parallel to the direction of the maximum far-field compression. However, coalescence of the wing-cracks may be in either tensile mode or shear mode, or a combination of both modes. The numerical results show qualitatively a reasonably good agreement with reported experimental observations for samples with similar flaw arrangements. The numerical results demonstrate that, with a confining pressure, the crack growth is stable and stops at some finite crack length; whereas a lateral tensile stress even with a small value will result in an unstable crack growth after a certain crack length is attained. Secondly, failure mode in a sample containing inhomogeneities on grain scale has also been simulated. The results show that the failure mode strongly depends on the mechanical and geometric properties of the grains and inclusions

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Annan samhällsbyggnadsteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Other Civil Engineering (hsv//eng)

Nyckelord

Mining and Rock Engineering

Gruv- och Berganläggningsteknik

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