A macro-modelling approach for the analysis of masonry-infilled RC frames with different opening dimensions and locations

Abstract

Abstract Based on structural experiments and a micro finite-element analysis in ABAQUS, the interaction between an infill wall and an RC frame under lateral loads was investigated. According to the load transmission mechanism and the stiffness and strength contribution of infill walls, a macro-model with multiple blocks around the opening (represented as double diagonal struts) was proposed. The macromodel was established in OpenSees to simulate the discontinuities in the force transmission paths and the stress states around the openings of the infill walls. In a comparison with the experimental data, the proposed macromodel was proven to adequately simulate the different failure modes and hysteretic behaviours of masonry infills with different opening modes and locations. By using the opening rate and opening position as variables, 52 macro-modelling analyses of masonry-infilled RC frames with different window and door openings were carried out. The results showed that the presence of masonry infill walls greatly increased the initial stiffness and ultimate load-bearing capacities of single-story, single-bay RC frame structures. A larger opening rate resulted in lower initial stiffness and ultimate load-carrying capacity values, which decreased more as the opening locations deviated further from the centre to the sides.