Experimental stress-intensity distributions in three-dimensional cracked-body problems

For over a decade, the first author and his associates have worked towards the development of an optical-experimental-modeling technique for predicting both the flaw shape and the stress-intensity-factor distribution in three-dimensional cracked-body problems where neither are knowna priori. The application is associated with subcritical flaw growth, the precursor to most service fractures. This paper presents an assessment of results obtained by applying the technique which consists of a marriage between frozen-stress photoelasticity and moiré analysis to measure the stress-intensity-factor distribution across a straight-front crack in a body of finite thickness.