Stresses from Variously Loaded Circular Cracks

A recently devloped theory for stresses around an arbitrarily loaded circular crack in an infinite body is reviewed, and examples are given illustrating its algebraic use for further analysis and numerical results it can give. It is shown how entities such as crack surface displacements and stress intensity factors are related algebraically to identifiable parts of normal and tangential loads on the crack. Since the functions underlying the theory are adaptable for computing, calculated stress patterns are given for key loads for cracks in large bodies. These cases are uniform normal load, tilted normal load, unidirectional shear, and uniform twist. While these results have their own inherent interest, they also provide good background for analyzing more complicated situations, such as in large bodies with superposed loads of differing kinds or in finite bodies where surface interactions effectively alter the crack loads in many ways.