Seismic assessment of infilled RC frame structures: analysis of the internal forces due to frame-infill interaction

This paper explores the complex behavior of infilled frames due to the frame-infill interaction under seismic loads. Through a micro-modeling approach, the STKO software platform was used to generate 2D nonlinear models of selected experimental tests. These models are used to assess shear demand within the RC frame. Furthermore, the study introduces an analytical relationship to correct shear demand at column ends. This formula complements the basic equivalent strut approach, accounting for frame-infill interaction, by connecting additional shear demand, axial force on equivalent struts, and the geometric/mechanical attributes of infilled frames.