Elasto-plastic behaviors of the one-bay and one-story gable steel frame structures, subjected to the repeated variable lateral loads under constant vertical ones, are analyzed using the hybrid stress finite element method. The specific and promising approach, which is shown in the Refs.1)-3) and is very advantageous to trace the elasto-plastic responses of steel structures under repeated variable loading, is employed. The skeleton and steady hysteretic characteristics of the frame under consideration are examined critically and circumstantially, comparing with the ones under monotonic loading, and their cause and mechanism are discussed and reasonably explicated.
