Numerical Investigation of Steel Frames with Corrugated-Web Reduced Beam Sections for Enhanced Progressive Collapse Resistance

Following our earlier work on reduced beam section (RBS) connections, this study examines a new set of corrugated-web cell configurations for steel moment-resisting connections. A finite element model, validated against four experimental investigations reported in the literature, was used herein to assess the effects of cell geometry, transverse depth, and position relative to the column face on load-carrying capacity, deformation capacity, and damage evolution. The results show that the proposed configurations alter the stress distribution and shift the plastic hinge away from the beam–column joint, thereby decreasing the stress concentration in critical areas. Structural performance was highly sensitive to the interaction between cell geometry and its position along the beam. The curved cell configuration performed best when located near the column face, whereas the angle-shaped and trapezoidal configurations performed better farther from the column face, with the angle cell configuration giving the best overall response among all four. Comparatively lower efficiency was observed with the double curved configuration. To gain further insight into the viability of the proposed approach, the optimal designs derived from simplified beam analyses were then incorporated into a validated two-story steel sub-frame model. These results confirm that the selected geometric properties remain effective at a larger structural scale, preserving the beneficial effects observed in the beam-level analysis. These results demonstrate the potential of the proposed system to improve steel moment-resisting connections and provide a basis for further research on optimizing more advanced connection design techniques.