Abstract
The present situations of design and construction on concrete filled steel tubular structures in Japan are described. The outlines of research works conducted in Kyushu University, such as the elasto-plastic behaviors of frames, the ultimate strength and deformation capacity of members, the limiting values of width(diameter)-tothickness ratio of cross sections, the stability and strength of slender columns, and the behaviors of truss frames are discussed. The design strengths of columns based on several foreign design standards are compared with Japanese design strength.
