The buckling strength of a compressive steel member is determined based on theoretical and experimental investigations in current steel structural design. The design buckling strength is calculated corresponding to the slenderness ratio and it is small compared with the yield compressive strength, particularly in the elastic region. We study how the strength of the compressive steel member reaches the yield strength regardless of the slenderness ratio with the aim of simplifying the design formula and obtaining esthetically good design of the member. To obtain the yield strength, we adopt a hybrid section member, which is composed of mild and high strength steels, in the plastic buckling region and a gradually extended section member toward the center of the member in the elastic region. The box-shaped and H-shaped steel members are used in the analyses.
