Energy Release Rates for Various Defects
It is known that the energy-release rates associated with translation, rotation, and self-similar expansion of cavities or cracks in solids are expressed by path-independent integrals J, L and M, respectively. These integrals are of interest to NDE in that they can be used to characterize nondestructively defects in solids.
It is shown that these integrals for a crack may be evaluated by first considering an ellipse and then performing a limiting process. This obviates dealing with singularities at crack tips and holds promise for a more efficient numerical method in complicated cases, since modeling of singularities is always associated with difficulties and uncertainties.