Strain energy density to assess mode II fracture in U-notched disk-type graphite plates

The brittle fracture criterion, namely the strain energy density (SED) over a control volume, which embraces the notch edge, is utilized in the present research to assess the experimentally obtained fracture loads of several U-notched Brazilian disk (UNBD) specimens made of a type of commercial graphite under pure mode II loading. The results show that the SED criterion could successfully predict the fracture loads of graphite specimens for different notch tip radii with an average discrepancy of about ±10%. It is proved in this investigation that not only the SED criterion works well on brittle fracture of notched graphite components under pure mode I, mixed mode I/II and pure mode III loading conditions, but also under pure mode II loading. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions. nav.