Refinements in the characterisation of mode-mixity and small scale yielding at sharp notch roots

•Presents informative calculations for designing/analysing sharp notch experiments.•Presents an improved characterisation of mode mixity at sharp notch roots.•Enables small scale yielding limits simultaneously to be plotted with mode mixity.•Applies the proposed method to sharp V-notch experimental data in the literature.

This paper uses a modified formulation of Williams’ asymptotic solution to examine the plastic zone near the root of sharp V-notches. A method for assessing whether the plastic zone is ‘mode I like’ or ‘mode II   like’ or mixed-mode in character is presented. Small scale yielding limits are also calculated. This analysis is then applied to monotonic, mixed-mode experimental test data reported in the literature. The results indicate that: (i) most tests were carried out within 5%5% small scale yielding and (ii) the plastic zone of practical engineering components is likely to be either mainly mode I or mixed-mode in character.