Use of the ?1 criterion in evaluating the long-term strength of structural steels in plane stress

Abstract

1. Under plane stress conditions, an estimate of high-temperature long-term strength for structural steels obtained from the value of the maximum tensile stress will not be overstated only for the case of biaxial tension. 2. If a study of high-temperature long-term strength (creep strength) in biaxial tension is conducted on thin-walled tubular specimens and the results are compared with data for the simple axial tension of the same tubes, the presence of work hardening in the axial direction will lead to the appearance of a range of stress states in which estimates of long-term strength made according to the maximum tensile stress σ1 will be exaggerated. 3. The limits of the range of applicability of the criterion σ1 in biaxial tension are determined by Eqs. (15) and (16).