Abstract:Recently, designs of high‐rise buildings have become more complex. Various types of buildings result, such as buildings with a semicircular plan, and buildings in which the upper floors are larger than the lower floors.The authors have developed a three‐dimensional (3‐D) dynamic analysis system, ‘Super DYNAMICS’, which considers the nonlinear behavior of each structural member in order to analyze the structural behavior of such complex steel buildings under severe earthquakes.This system is mainly operated on a supercomputer because of the large number of calculations required for the member level dynamic analysis.This paper first describes the general concepts of the system and the 3‐D dynamic response analysis methods, based on the nonlinear behavior of each member under axial force and biaxial bending moments, and then examines and demonstrates the precision of the yield surface of steel members created by multispring models, and the ability of the system to trace the behavior of members and frames after yielding. It shows, in addition, actual examples of a static and a dynamic analysis by three‐direction ground motion applied to a 19‐story steel‐frame