Abstract
For a steel structure subjected to the fluctuating horizontal forces caused by strong earthquakes, the accumulation of deformation plays as a key parameter to evaluate the restoring force characteristics deteriorated by such as local buckling. In this study, the axial force is adopted as the constant external force and limits of the axial force to keep the aseismic safety are derived by computations for the square tube steel beam-columns, which are based on conditions of the accumulation of the centroidal axial strain. Validity of limitations is examined by the comparison between analytical and test results.
