COMPENDIUM OF T‐STRESS SOLUTIONS FOR TWO AND THREE DIMENSIONAL CRACKED GEOMETRIES

Conventional theories of fracture assume that the state of stress and strain in the vicinity of a crack tip, and so the onset of failure, is characterised by a single parameter. The physical extent of these single-parameter fields is determined by the geometry, size and mode of loading of the engineering structure or test specimen containing the crack. It is now recognised that fracture toughness is a material property characterised by a single parameter J only in special circumstances which involve a high degree of constraint at the crack-tip. In general the apparent toughness of a material changes according to the shape and size of the cracked configuration and the mode of loading imposed. Recent analytical, numerical and experimental studies have attempted to describe fracture in terms of both J and a second parameter. The reason for the second parameter is to provide further information, which J on its own is unable to convey, concerning how the structural and loading configuration affects the constraint conditions at the crack-tip. One particular candidate parameter is the elastic T-stress which is directly proportional to the load applied to the cracked geometry. This paper brings together published solutions for the T-stress for a range of two and three-dimensional cracked geometries and presents some new results calculated at AEA Technology. The application of two-parameter fracture mechanics is a subject of ongoing development and users of the data in this paper are recommended to seek expert advice regarding applications to specific structural integrity assessments.

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