INELASTIC RESPONSE ANALYSIS OF REINFORCED CONCRETE SPACE FRAMES UNDER BI-DIRECTIONAL EARTHQUAKE LOADS

A computer program was developed to simulate ۳-dimensional nonlinear earth-quake response of reinforced concrete structures. The interaction between biaxial bending moments and axial force in the column member was considered using inelastic fiber elements at the two ends, the hysteresis relations of which were based on those of the materials. In this paper, medium-rise reinforced concrete space frames were analyzed under uni- and bi-directional earthquake motions, in which column-to-beam strength ratios were varied. The magnification factors for the design of the columns were investigated to ensure beam-yielding mechanism taking dynamic and biaxial effects into account