Computational Model for the Flexural Capacity and Stiffness of Eccentric RHS X-Connections under Brace Out-of-Plane Bending Moment

Abstract

This paper aims to establish a precise and concise formula for quantifying the out-of-plane flexural capacity and initial stiffness of unstiffened eccentric steel rectangular hollow section (RHS) X-connections. In this paper, an experimental study is first conducted and corresponding numerical simulation is subsequently carried out. Based on the failure mode and deformed pattern observed in the experimental and numerical studies, two yield line models and a frame-beam model are developed to predict the out-of-plane flexural capacity and flexural initial stiffness of the X-connections. Then, parametric analyses are conducted to verify the rationality of the form of capacity theoretical formula, and to derive an initial stiffness theoretical formula that is significantly simplified. Finally, the predicted out-of-plane flexural capacity and initial stiffness of the X-connections are respectively compared with those of the corresponding experimental and numerical results using the simplified formula. This comparison confirmed the validity of the proposed formula.