Summary

The magnification of stresses at geometric stress concentrations is of great importance in engineering design. In particular, problems of frac­ ture are all the result of local concentrations of stresses arising from abrupt changes of shape or geometrical discontinuities. Typical exam­ ples are notches, grooves, fillets, flaws and cracks. Their shape and degree of sharpness can greatly influence the load bearing capacity of structural members. From the designer's point of view, a fracture analysis will involve two major concerns: (1) a stress analysis of the geometrical disturbance, and (2) a postulate predicting the event of fracture itself. Comprehensive treatments of the elastic stress dis­ tributions around a wide variety of geometric cavities are available in the open literature and will not be repeated in this volume. The number of proposed failure criteria is equally exhaustive. However, there is still no coherent treatment of failure for all geometric cavities regardless of their shapes and sizes. This fifth volume of the series on Mechanics of Fracture attempts to join the behavior of sharp discontinuities such as cracks to that of notches or cavities and to provide a few typical analytical methods of stress solutions. The finite element method has been purposely left out, for it is now becoming common procedure in cases too complex for analysis. One of the major applications for fracture mechanics analyses is an assessment of the influence of defects on the strength of structural components.