Determination of averaged stress triaxiality of notched tensile test specimen using shape parameter and material property

This paper presents an empirical formula for deriving notch triaxial stresses using only material constants related to notch geometry and deformation. As the tensile test progressed, the initial notch shape deformed and the triaxial stresses changed accordingly. Notched tensile test results for various materials were synthesized and the tensile test of each material was simulated using finite element analysis. The relationship between notched stress triaxiality, specimen shape, and material constants, derived from tensile test simulations, was analyzed. Based on this, a formula was proposed to calculate the average stress triaxiality of notched specimens, using only the notch shape and material constant and without performing finite element analysis.