THE IMPLEMENTATION AND PRELIMINARY VERIFICATION OF AN ALGORITHM FOR THE ANALYSIS OF FATIGUE CRACK GROWTH AT NOTCHES

摘要

In recent years an analysis algorithm has been under development which attempts to address the occurrence of cyclic plasticity at stress concentrations and then to model the growth of fatigue cracks at these concentrations using a modified LEFM approach. This algorithm utilizes either Neuber's rule or Glinka's strain energy density method to estimate elastic-plastic response stress distributions on a critical plane (the plane on which mode I cracking will occur). These stress distributions are then used in conjunction with an appropriate weight function or Green's function to calculate a stress intensity factor (SIF). These calculations are made on a cycle-by-cycle basis, thus permitting the calculated SIFs and associated crack growth rates to be dependent on both the formation and evolution of residual stresses at the notch root.