Numerical modeling of perforated flat slabs strengthened with angle plates

Abstract This study numerically investigates flat slabs with openings near columns, strengthened using steel angle plates bolted to the column faces and slab on both tension and compression sides. The vertical leg acts as an equivalent column capital, while the horizontal leg functions as a drop panel. Non‐linear finite element analysis using the concrete damaged plasticity model in ABAQUS examines punching shear resistance, load–displacement response, crack patterns, and deformation. The model was first verified against previous test results, with analysis results compared to design code estimates. The proposed strengthening method significantly improves ultimate load capacity by 65% to 91%, enhancing stiffness, ductility, and energy absorption. This shifts failure from pure punching to flexural deformation beyond the reinforced zone. This paper also presents a yield line theory‐based approach for estimating flexural capacity.