A Photoelastic Determination of Stress Intensity Factors for Corner Cracks in a Bolted Joint

Three-dimensional photoelasticity was used to measure mode I stress intensity factors of corner cracks in a double-shear bolted joint. A model of the joint assembly was manufactured from a photoelastic material and three different corner cracks were introduced using a cutting wheel. After the stress freezing process, slices along the crack fronts were cut and analyzed using three different photoelastic procedures. There was good correlation between the methods of analysis. Stress intensity factors of these cracks were found to vary along the crack front with a maximum at the bore of the hole and a minimum on the surface of the plate. This implies that the cracks are likely to grow more rapidly along the bore.