Impact of member interaction on static mechanical performance of steel-aluminum composite gusset joints

Abstract

This study investigated the influence of member interaction in steel‑aluminum composite gusset joints on their static mechanical performance. Analysis of 11 joint types, compared with pure steel and pure aluminum alloy gusset joints, reveals that steel members, having greater stiffness than aluminum alloy members, exhibit a larger stress distribution. The composite gusset joints undergo non-centrally symmetrical deformation and member torsion. The interaction between the members significantly affects the initial stiffness of the composite gusset joints. Specifically, aluminum alloy members increase the initial stiffness of adjacent steel members but reduce the stiffness of steel members in secondary adjacent or opposite positions. Conversely, steel members have the opposite effect on aluminum alloy members. Additionally, increased joint constraints and the member's moment of inertia amplify the effects of member interactions on initial stiffness. Analysis of 3960 moment-rotation curves clarifies the interaction coefficient rules and presents a method for calculating the initial stiffness of steel‑aluminum composite gusset joints.