A shallow crack assessment scheme for generalised material behaviour in tension

A previously proposed estimation procedure for J-strain relationships in power law materials has been further augmented so that it can be used for general engineering applications to real material stress-strain curves. The extension covers two important aspects of material curve representation. First the effects of including the material constant ? of the power law on J are included—this inclusion facilitates a more accurate curve fitting of real material curves. Secondly, a set of equations is presented to account for the presence of a perfectly-plastic yield plateau, in addition to the strain hardening portion. The validity of the augmented procedure was confirmed by comparison with finite element solutions on specimens with fictitious and real material curves.