Modification of the G-criterion for crack propagation subjected to compression

✍ Scribed by B. Shen; O. Stephansson

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 801 KB
• Volume: 47
• Category: Article
• ISSN: 0013-7944
• DOI: 10.1016/0013-7944(94)90219-4

✦ Synopsis

Ustract-Brittle materials subjxted to compression can fail and the resulting cracks can propagate in mode I and mode II in two dimensions. The maximum strain energy rekase rate criterion (G-criterion) is examined for its capacity of pmdicting the mixed mode crack propagation. When this criterion is applied to an hclinal crack subjected to compression, it pmdicta the shear Cdlum but not the tensile failure. The reason for this phenomenon is discursed and a new form of this criterion, namely the Fcriterion. is proposed. The F-critexion usea the sum of norm&cd G, and Gu (F = G,/GL + G,/G,) as the fwtor which represents the crack propagation and its direction. Impkmental into the numerical displacement discontimdty method (DDM), the F-criterion can predict both mode I and mode II propagation of a crack system. The capacity of the F-criterion in predkthg both mode I and mode II propagation ia demonstrated for two models subjected to uniaxhl compression for a single crack and a set of two cracks. The num&al simulations show good agreement with the results of laboratory experiments amductai on rocks and gypsum.