Elasto-plastic stress and strain behaviour at notch roots under monotonic and cyclic loadings

Notch deformation behaviour under monotonic and cyclic loading conditions w as investigated using circumferentially notched round bar and double-notche d flat plate geometries, each with two different notch concentration factor s. Notch strains for the double-notched plate geometry were measured with t he use of miniature strain gauges bonded to specimens made of a vanadium-ba sed microalloyed steel. Elastic as well as elasto-plastic finite element an alyses of the two geometries were performed. Notch root strains and stresse s were predicted by employing the linear rule, Neuber's rule and Glinka's r ule relationships under both monotonic and cyclic loading conditions. The p redicted results are compared with those from elastic-plastic finite elemen t analyses and strain gauge measurements. Effects of notch constraint and t he material stress-strain curve on the notch root stress and strain predict ions are also discussed.