Theoretical and experimental study of specimens with stress concentrators in dependence of stress triaxiality

The literature presents several results referring to multiaxial tests of stress concentrators specimens. Different types of these specimens are presented and they were used accordingly to the stress triaxiality as follows: butterfly specimen for high degree of stress triaxiality, plane specimen for medium state of triaxiality and cylindrical specimen for low degree of triaxiality. This article shows the results of experimental determinations, finite element analysis and theoretical study of two types of plate specimens with stress concentrators and it aims to obtain high stress state in failure section (volume), more uniform stress distribution and stress ratio to be constant until failure.