Numerical study of reinforced concrete frame-infall wall interaction

Abstract

The frame- infill systems, an economic means to enclose and partition space, are used throughout the world for architectural needs or aesthetic reasons. However, because of the complexity of the problem and absence of a realistic, yet simple analytical model, the combination of masonry infill panels is often neglected in the numerical analysis of building structures. When subjected to strong lateral load, infill panels tend to interact with the bounding frame and may induce a load resistance mechanism that is not accounted for in the design. This may lead to substantial inaccuracy in predicting the lateral stiffuess and strength of the structure. The finite element (FE) technique has been effectively used to analyze the behavior of masonry infilled Reinforced Concrete (RC) frames. The finite element analysis procedure used in this study has been able to investigate the effect of incorporation of masonry infill panels with or without opening in the bare RC frame and to simulate test result of infilled RC frames which verify the effectiveness of such FE modeling. From extensive numerical analysis and parametric study, it has been found that the infilled panel increases the lateral stiffuess of an RC frame by a substantial amount and the contribution of infill to the total stiffuess of infilled frame changes with the presence of door or window opening in the masonry infill panel. Investigations have also been done for various support conditions and it has been observed that support condition has considerable effect on the stiffuess ofthe structures. The finite element analysis methodology has been proven to be an effective tool to reasonably investigate the behavior of structural components. However sometimes numerical analysis has been found to be time consuming and complicated. To overcome these problems attempts have been made in this study to develop simplified equation to find out the stiffuess of masonry infilled RC frame and finally verification of the developed equations have been performed with the existing experimental result. This approach can now be effectively used to determine the stiffness of bare frame, masonry infilled RC frame with or without door and window opening.