%0 Journal Article %T Analytical Modeling of Masonry Infilled RC Frames and Verification with Experimental Data %A S. Skafida %A L. Koutas %A S. N. Bousias %J Journal of Structures %D 2014 %R 10.1155/2014/216549 %X The assessment of the response of masonry infilled RC frame structures has been a major challenge over the last decades. While several modeling approaches have been proposed, none can cover all aspects observed in the tests. The present paper introduces a simplified model built on the approach established by Crisafulli and Carr (2007) and addresses its calibration and implementation in a nonlinear analysis software for the evaluation of the in-plane lateral response of infilled RC frames. The proposed model uses a set of elements/springs to account separately for the compressive and shear behavior of masonry. The efficiency of the modeling approach is validated with available experimental data, yielding satisfactory matching. The most intricate issue encountered when attempting to represent a masonry panel is the plethora of the material parameters involved and the lack of complete and available test results. Thus, the numerical investigation is accompanied by a parametric study on the sensitivity of the model to the various parameters to identify the critical modeling quantities and provide guidance on their selection. 1. Introduction The evaluation of the seismic performance of masonry infilled RC frame structures is a widespread problem that has not yet been resolved despite the numerous efforts reported in the literature during the last decades. As a result, and contrary to the finding from the response of masonry infilled structures under actual seismic action, infill is often treated as nonstructural elements and is omitted by the analysis models. Nevertheless, the uncertainty associated with the interaction of the infill with the bounding frame and the different failure modes exhibited, the variability of the material properties, geometrical configurations, and construction methods reveal the complexity of the problem and justify the lack of unified, reliable, and widely accepted approaches for the design and assessment of structural systems that include infill panels. From the computational point of view, the modeling techniques used for the analysis of infilled frames can be divided into two main categories: (i) local or micromodels and (ii) simplified macromodels. The first category is based on the nonlinear finite element method and strives to provide an accurate representation of the frame-infill interaction at the local level. Many of the researchers, who adopted this methodology, for example, Lotfi [2], Lourenco [3], Attard et al. [4], and Mehrabi and Shing [5], used a combination of continuum and interface line elements to simulate the %U http://www.hindawi.com/journals/jstruc/2014/216549/