عنوان مقاله [English]
In this researches the effect of masonry infill in concrete frames behavior have been proceed by two methods: three strut and diagonal one strut, that three strut method is known as one of last presented Technique for infill masonry modeling so diagonal one strut method is suggested method of retrofit construction for modeling of masonry infills. Three aspects of frames that have been investigated are height (number of story), thickness and modeling method of infills. These frames have been loaded and analyzed based on 519 & 2800 codes. and designed according to ninth discussion of structures public (national) institutes and then analyzed based on nonlinear pushover analysis in two state with and without infill by sap 2000 software, and the amount of masonries infill effect on the frames behavior has been investigated. The results represents that infills increase, strength, stiffness and improve performance level and decrease of hinges number, but in most of analysis states, infills have been destroyed completely and diagonal one strut method in most cases represented conservative results rather than three strut method for frames. Amount of stiffness increment and drift decrease, because of infill presence would be decrease by increase in height. By this, ignorance of infills in lower fames can result in incorrect design and increase of infills thickness did not have such influence on the improve of studied frames behavior in this research.