An experimental method for evaluating mode II stress intensity factor from near crack tip field

A new experimental approach for evaluating stress intensity factor was recently suggested by the authors (He et al. in Int J Solid Struct 78–79:131-137, 2015b). It is based on a linear relationship between the remote stress intensity factor and the out-of-plane surface displacements in the close vicinity of the vertex point. Dimensionless considerations, 3D FEM and DIC technique were attracted to establish and validate this relationship. However, these new developments were limited to through-the-thickness cracks subjected to mode I loading only. This brief note extends the above-mentioned approach to mode II and, eventually, to mixed mode loading.