Steel Members Subject to Axial Tension and Biaxial Bending Moments

According to Sect. 1.6.2 of the current edition (1978) of the AISC Specification, steel members subject to both axial tension and bending stresses shall be proportioned at all points along their length to satisfy the requirements of Formula (1.6-1b). It is well known that Formula (1.6-1b) accounts for the cross-sectional strength of the members and that this form of the strength interaction equation is conservative for most sections and provides a factor of safety of at least 1.67 against the attainment of the ultimate moment capacity of the cross section.