Progressive Collapse Performance Study on Fuse Angle Designs in Rigid and Semirigid Connection

This study investigates the progressive collapse performance of an innovative replaceable fuse angle design in rigid and semirigid beam-column connections in moment-resisting steel frames. Progressive collapse, triggered by the failure of a primary structural element, often concentrates damage at beam-column joints, underscoring the importance of joint integrity for load transfer and structural stability. Using ANSYS 2024, fully welded beam-column connections were modelled, and replaceable fuse angles were integrated to enhance seismic resilience by relocating plastic hinges away from critical joints. A parametric study evaluated the influence of fuse angle angles. Load-displacement curves, force-deformation relationships, and plastic strain distributions were analysed to assess the effectiveness of the fuse angles as sacrificial elements for energy dissipation and controlled failure. Numerical results, validated through calculations, demonstrate that optimized splice configuration significantly improves energy dissipation and structural stability. This research advances the development of replaceable connections, offering a practical solution for enhancing the resilience of steel structures under seismic and accidental loading conditions. The results demonstrate that the application of fuse angles significantly improved the load-carrying capacity and delayed the onset of local failure at critical joint regions. Among the configurations studied web splice only, flange splice only, and combined web and flange splices the combined configuration exhibited the most favorable performance, reducing stress concentrations at the beam-column interface and enhancing overall energy dissipation. The use of replaceable fuse elements facilitated controlled yielding away from the joint core, ensuring better damage tolerance and easier post-event repair.