An analytical-experimental estimation of elastic linear zone for photoelastic mode I SIF extraction

The traction continuity condition is used to delineate the elastic linear zone (ELZ) for the extraction of the Mode I stress intensity factor (SIF) from photoelastic data. The procedure requires an estimation, with the aid of experimental data, of some non-dimensional quantities which are the ratios of unknown parameters of the LEFM equations and the corresponding ones for an infinite body problem. Furthermore, the crack tip nonlinear zone is assumed to admit of plastic deformation with small-scale yielding.The estimation of the ELZ thus obtained seems to predict well the experimentally observed one.