Photoelastic study of a center-cracked plate – The lateral load effects

In this paper, the method of photoelasticity is used to study the effect of biaxial loading on isochromatic fringe patterns around a central crack in a plate. First, utilizing the mathematical relations of isochromatic fringes, the effects of a load parallel to the crack direction on the shape and size of the fringes are studied. Since the parallel-to-the crack load affects mainly the T-stress, a method is used to calculate the T-stress directly from the photoelastic test results. In order to evaluate the analytical results, a photoelastic test program is performed on a cruciform cracked specimen. The results of these experiments are used to study the effect of parallel-to-the-crack load on the isochromatic fringe patterns. The T-stress calculated from the experimental data is compared with the results obtained from finite element analysis. It is shown that there is a good correlation between the experimental and numerical results.