FE parametric study of circular Reduced Web Section (RWS) connections subjected to cyclic loading

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Circular reduced web section (RWS) openings provide a practical weakening strategy for retrofitting welded steel moment connections by relocating inelastic demand away from the beam‐to‐column interface. This paper defines a compact suite of performance metrics for cyclic assessment of fully restrained circular RWS subassemblies subjected to AISC 341 cyclic loading protocol. A validated three‐dimensional finite element model is used to generate a database of 7,575 numerical specimens spanning European IPE sections, steel grades S235, S275, and S355, and span‐to‐depth ratios 2 L/h =6 to 14. Backbone‐based ordinates and hysteresis‐derived measures are proposed to quantify strength retention, high‐drift stability. Database‐level trends show that opening geometry primarily governs post‐yield behaviour, with larger web openings and close to the column face most detrimental at low span to depth ratios. In addition, robust geometry corridors meet AISC criteria for special moment frames with less than 20% strength degradation while preserving stability. Selected well‐proportioned openings can match or exceed solid web stability and high drift.