Parametric numerical study on the seismic performance of beam-to-double-skin concrete-filled steel tubular column connections

Earthquakes are natural phenomena that can cause significant human and financial damage, making the design of earthquake-resistant buildings crucial.Beam-to-column connections are vital in any structure, and further research is needed to understand the parameters influencing their behavior.This is especially important in buildings with double-skin concrete-filled steel tubular columns (DSCFT).The aim of this study was to explore the impact of void percentage, concrete strength, and inner skin thickness on beam-to-DSCFT column connections.After validating numerical modeling, three model groups with eleven models were analyzed under cyclical loading.Results indicate that increasing the void percentage in the column from 10% to 100% reduces the maximum tolerable moment from 519.49 to 354.64 kN.m, changes rupture mode from tensile to buckling, and decreases cumulative dissipated energy.Conversely, increasing concrete strength from 20 MPa to 70 MPa raises the maximum tolerable moment from 507.698 to 524.24 kN.m, with a cumulative increase in dissipated energy.Additionally, increasing the inner skin thickness from 5 mm to 15 mm raises the maximum tolerable moment from 506.978 to 520.892 kN.m, while reducing cumulative dissipated energy.