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 buildings, masonry elements can be found in frame structures as infill panels which function as partitions and/or external walls. During an earthquake these elements act as structural elements and impose a large degree of nonlinearity on the behavior of framing system. In this study, a micro-modeling procedure is proposed utilizing finite element analysis to model masonry infilled reinforced concrete moment resisting frames (RCMRFs). After calibration using material tests and standard masonry components, 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 substantially 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 seismic behavior of such structures. The developed strategy can also be used to propose new simplified models or precise existing ones such as equivalent diagonal strut model.