Theoretical determination of reference stress for partially penetrating flaws in plates

Abstract The reference stress concept is a very powerful tool for use in the stress analysis of non-linear materials. It can be applied to estimate the deformation and fracture behaviour of flawed and unflawed components. When applied to flawed components it is employed in conjunction with fracture mechanics concepts to predict failure. The aim of this paper is to develop a reference stress solution for partially penetrating defects in plates which are subjected to combined axial and bending loading. A solution relevant to ‘global’ collapse of the entire cross-section containing the defect is obtained. The treatment represents the defect by a circumscribing rectangle. A range of shapes and sizes of defect (i.e. rectangle) is considered. As expected, it is found that smaller reference stress values are obtained for the ‘global analysis’, particularly for large defects, than from those that are produced from estimates based on ‘local’ collapse of the uncracked ligament ahead of the defect.