Experimental–numerical hybrid stress analysis for a curving crack in a thin glass plate under thermal load

The stress fields around an oscillating crack tip in a thin plate are studied using an experimental–numerical hybrid method. Instantaneous phase-stepping photoelasticity using a CCD camera equipped with a pixelated microretarder array is used for measuring the stress fields around a propagating crack tip. Not only the principal direction but also the principal stress difference around a growing crack is obtained. Then, the stress distributions around a crack are evaluated by the experimental–numerical hybrid method. Results show that the proposed hybrid method is effective for the study of crack growth behavior in the glass plate. The results obtained in this study show that the compressive stresses exist around the tensile stress region at the crack tip. It can be considered that the existence of the compressive stress distribution surrounding the tensile stress field at the crack tip leads to both the high value of the stress intensity factor and the crack oscillation.