Micro-modeling of Masonry Infilled RC Moment Resisting Frames to Investigate Arrangement of Compressive Diagonal Struts

Accurate modeling of masonry has been a major concern of the researchers in the past decades. Besides reinforced and unreinforced masonry structures, masonry can be found in frame structures as infill panels which are used as partitions and/or external walls. These elements role as a part of structure and introduce a large degree of nonlinearity into the system. In this study, a micro-modeling procedure is introduced using finite element analysis to model masonry infilled reinforced concrete moment resisting frames (RCMRFs). After calibration using material tests and small masonry assemblage experiments, the model will be used to predict the behavioral parameters and failure mode of this type of structures. It will be shown that the proposed procedure is fairly successful in estimation of the stiffness and strength and can simulate the failure mode of the infilled RCMRFs tested under semi dynamic lateral loading. Finally, the process of formation and arrangement of compressive struts in different stages of lateral loading in the infill wall will be discussed. As a result, it will be concluded that the proposed modeling strategy can be used as a means to better recognize the behavior of such structures and to propose new or precise existing simplified models such as equivalent diagonal strut model.