Effect of specimen thickness on mode I stress intensity factor in photoelastic investigations

The determination of the Mode I stress intensity factor (SIF) in the case of cracks and geometrical discontinuities in three-dimensional photoelastic models involves usually an approach in which the stresses in the model are frozen or locked, and a slice containing the region of interest is cut from the model for analysis. Questions arise related to the acceptable thickness of the slice, taking into account the requirement to obtain a satisfactory or consistent value for SIF from photoelastic data. Other questions are concerned with the domain within which the observed photoelastic data give reasonably consistent values for SIF. The present investigation provides some findings pertaining to these questions