Practical Analysis of Almost Circular Tensile Cracks under Uniform Loading

We study two different approaches to the evaluation of the stress intensity factors (SIF) for circular cracks one of which is based on the Rice integral formula and the second (Panasyuk) approach deals with the analysis of the stressed state outside an imaginary circular crack. It is shown that the Panasyuk approach is more accurate from the mathematical point of view as it is physically grounded and based on the three-term approximation of the stress field. The proposed practical procedure for the evaluation of the SIF proves to be very efficient and gives good results for irregular cracks.