Experimental study of parameters affecting the behavior of moment-Resisting steel frames including masonry infill walls

The effect of masonry walls on the behavior of steel frames is one of the important issues of seismic response of structures. In this experimental study, the behavior of steel frames with masonry infill walls has been investigated and the effect of brick type, wall thickness, and wall openings has been evaluated. Seven 1:3, single-span and one-floor steel frame specimens were tested under the influence of quasi-static loading. All specimens except one had an infill wall. In these samples, three types of brick materials, two types of thickness and two types of openings were tested and evaluated. The bricks used in the infill walls were non-perforated clay bricks, perforated clay bricks and common lightweight clay blocks in Iran. The type and dimensions of openings were also adjusted according to the common dimensions used in a variety of buildings. The results show that the type of materials used in the infill walls, the wall thickness and the presence of openings have a significant effect on the seismic behavior of the structures. The infill wall significantly reduces structural ductility, while increasing its stiffness and ultimate strength. Therefore, in moderate to strong earthquakes, the infill wall has a negative effect on the structural behavior. In addition, the infill wall increases strain due to the imposed of localized deformation in the frame members. However, it reduces the strain on the panel zone.