Localized force generation by masonry infill wall-steel frame interaction

Investigating the different effects of masonry infill panels on the behavior of frame structures is an on-going research topic in performance-based earthquake engineering. Among these, the local effects of infill panels and the changes they impose on the internal forces of the members of frame structures are very important. One of the unwanted corollaries of ignoring these effects is the formation of unpredicted plastic hinges in critical regions of frame components, which sometimes lead to the collapse of the entire structure. In this article, a thorough parametric study has been conducted using 38 finite element models to examine the variations in internal forces (bending moment, shear force, and axial force) generated in the beams and columns of these models. The results indicate that although in some cases the presence of infill panels has a positive effect in decreasing the internal forces of the frame structure’s members, it also has the potential to adversely increase these forces by several orders of magnitude in certain situations. Finally, the performance of single- and multi-strut models in predicting the infill-induced changes in the frame’s internal forces will be assessed.