Comparison of experimental and analytical results on masonry infilled RC frames for monotonic increasing lateral load

Abstract

The aim of the paper is to give a suggestion to the structural engineers to model masonry infilled reinforced concrete frames. We made several experiments, and developed some numerical models. One question is how to model the infill masonry for monotonic increasing lateral load? Three different numerical models were investigated. The simplest model is the equivalent diagonal strut model, where the masonry wall is replaced by a compressed diagonal strut. The next model is the orthotropic surface model, where the masonry wall is taken into account as a membrane or shell surface. Between the RC frame and the boundary of the surface are modelled with special spring and contact elements. The last model is called ``suggested sophisticated model´´, where the bricks and the mortar layers are separately modelled. The brick is taken into consideration as an orthotropic membrane element, while the mortar layers are substituted with short perpendicular and diagonal equivalent compressed struts. We give the necessary data to the material properties. We suggest a bilinear stress-strain relationship that allows reach the experimental results more accurately than the usage of the material values in accordance with Eurocode 6.