The Effects of Amount and Location of Openings on Lateral Behavior of Masonry Infilled RC Frames

Abstract

Many design codes didn’t consider masonry infills as structural elements inside moment resisting frames. Therefore, their presence is not assumed in analysis and design process. While, in real they could affect strength, energy dissipation, ductility, stiffness and many other features of moment frames. The presence of masonry infills could also change the reaction of frames exposed to lateral loads like earthquake and wind. This issue becomes more important if the built frame was placed in seismically active region. In current study, the effects of opening location by placing openings in 3 different places and its percentage was evaluated. To this purpose an experimental scaled model was constructed and subjected to cyclic loading. Thereafter, by using simplified micromodeling, numerical modeling performed for extending studies. Subsequently, sensitivity analyses were done to survey the effects of opening ratio on the lateral behavior of intermediate RC moment frames. Analytical results indicate that the openings which were lo20cated at upper corner of the masonry infills will loss more strength. In all of the numerical specimens by increase in opening percentage the lateral strength was decreased. The lateral strength was negligible for infills with greater than 40% openings.