Influence of high stress triaxiality on mechanical strength of ASTM A36, ASTM A572 and ASTM A992 steels

This study aims at investigating the influence of high stress triaxiality on the yield strength and ultimate tensile strength of commonly used structural steels (ASTM A36, ASTM A572 and ASTM A992). To this end, axisymmetrically notched steel specimens are designed to generate a range of stress triaxialities. Yield strength and ultimate tensile strength of notched steel specimens are then determined using engineering stress-strain curves obtained from uniaxial tensile testing of notched specimens. Yield strength and ultimate tensile strength of all three types of structural steels are found to increase linearly with increase in stress triaxiality of test specimens. Based on experimental and complimentary finite element results, predictive equations are proposed to estimate increased yield strength and ultimate tensile strength as a function of stress triaxiality in structural steels.