Abstract
In this study, the effectiveness of masonry infill walls on steel frames with different beam-column connections under progressive collapse was investigated through a parametric study. A vertical force was applied to the center steel column to represent the progressive collapse of steel frames. This study focused on the three most common types of steel beam-column connections found in steel structures: shear, bolted, and welded connec-tions. Single-story (1/3 scale) steel-framed configurations with single shear and bolted beam-column connections and another infilled wall steel frame with welded connection from the literature were tested experimentally under a middle column loss event to validate the accuracy of 3D finite element models created with ABAQUS software. The verified finite element simulations were then used to study the performance of progressive collapse resistance for 12 various types of steel frames with masonry infill walls with three different types of beam-column connections. The effects of the full infilled frame, bare frame, and infilled frame with openings were explored. The size, location, and shape of the openings in the infilled frame, and the performance of these parameters with respect to the change in the type of beam-column connection were evaluated. In accordance with their mech-anisms of failure and load-displacement behavior, masonry infill walls were compared in flexural and catenary action phases. The findings show that infill walls considerably improve the steel building's structural strength and energy dissipation against progressive collapse.