A simplified non-linear structural analysis of reinforced concrete frames with masonry infill subjected to seismic loading

Structural performance of both new and existing building structures under seismic actions can be assessed with a wide range of nonlinear static procedures and time history dynamic analysis available in literature. Most of these procedures, such as time history dynamic analysis, are complex as they require sophisticated finite element modelling. Reinforced concrete (RC) frames with masonry infill, for example, pose great challenge in modelling both the composite material behaviour and their interactions. With significant effort directed towards sustainable infrastructure development, a simplified nonlinear analytical procedure for evaluation of RC infill frames subjected to incremental horizontal loading is developed that can be used easily in integrated structural performance and sustainability evaluation. The method, developed on the premise of truss analogy and utilising the pushover analysis, assumes that all structural members of the RC frame are truss elements with homogeneous material properties derived on the basis of a pure axially loaded system and the infill masonry is converted into strut elements. Stiffness modification through evaluation of nonlinear stress-strain states is employed to generate the overall force-deformation behaviour of the structural system. Experimental data available in literature is used to validate the procedure.