Nonlinear Analysis of Reinforced Concrete Frames under Cyclic Load Reversals

摘要

The report describes the static response in a study which endeavors to develop improved analytical methods for predicting the nonlinear static and dynamic response of multistory reinforced concrete frames. A new approach is proposed that consists of isolating the basic mechanisms controlling the hysteretic behavior of girders and columns into individual subelements which are connected in series to form the girder or column superelement. Two particular subelement models are developed: one describes the inelastic behavior along the girder accounting for the gradual spread of inelastic deformations at the girder ends, while the other models the fixed-end rotations that arise at the beam-column interface. The implementation of the superelement model requires the development of a numerical scheme which accounts for unbalanced moments between subelements. Such a scheme is developed within the framework of a special purpose analysis program for the nonlinear static and dynamic analysis of reinforced concrete moment-resisting frames. Correlation studies show that the analytical predictions for the proposed models show excellent agreement with the experimental results.