Analysis of Masonry Infill Panels Retrofitted with FRP Sheets in R/C Frames

Masonry infill walls are often used as non-structural elements. According to the past structural failure, ignorance of interaction between infill walls and enclosed frame may lead to the different seismic response for non-ductile building frames. The main contribution of this paper is to analytically investigate the behavior of reinforced concrete with masonry infill panels as participating structural. In doing so, a finite element model based on an equivalent strut method is conducted to represent the behavior of masonry panels. The strut model is calibrated using the results of the companion experimental program, which examined the cyclic behavior of infill panels with and without FRP sheets. Accordingly, a nonlinear spring element and a shell element are used to simulate the behavior of masonry strut elements and FRP sheets, respectively. The nonlinear static analysis (Push over analysis) is accomplished using SAP2000 [1] structural analysis software for a 10-story building with FRP sheets subjected to the gravity and lateral loading. The results indicate that the analysis method provides accurate estimation of structural response for both unretrofitted and retrofitted frames. Also, it was observed that although the FRP sheets increase the strength and stiffness of structures substantially, structural ductility remain without any considerable variation. Therefore a seismic retrofit strategy involving FRP sheets must be based on elastic response during strong earthquakes.