Effects of Central Opening in Masonry Infill on Lateral Behavior of Intermediate RC Frames

Despite not being taken into account in structural modeling, the complex behavior of masonry affects the seismic performance of structures. The main aim of this study is to evaluate the effects of infilled frames with different percentages of openings on reinforced concrete (RC) moment frames. Initially, an experimental model was constructed and subjected to loading. Afterwards, corresponding numerical analyses were carried out based on the experimental model. A simplified micromodeling method with respect to the numerical simulation of the experimental model was assigned. Subsequently, sensitivity analyses were performed to investigate the effects of the opening ratio on the behavior of intermediate RC moment frames. The analytical results indicate that increasing the percentage of the opening leads to a significant reduction in the lateral strength of the frame. The lateral strength of the masonry wall was negligible in masonry infills with openings greater than 40%. While prognosticating the behavior of buildings with masonry walls is complicated, determining the behavior of infilled frames with different percentages of openings will make it much easier to predict the damage pattern.