A Load-Displacement Relation Model for Framed Structures with Square CFT Columns, H-Shaped Steel Beams and Diaphragm-Stiffened Connections

Abstract

The purpose of this paper is to propose an analytical model for the elastic plastic analysis of moment-resistant frames consisting of concrete-filled rectangular tubular columns (CFRT columns), H-shaped steel beams, and typical connections using steel plate diaphragms. A hole in the diaphragm of such a connection is inevitable for concrete casting, and might result a low diaphragm rigidity and a plastic local deformation around the beam flange joint. The eight cruciform subassemblages were tested in order to develop the analytical frame model in which the local deformations at connections were taken into account. The model accuracy is demonstrated in comparison with the experimental data base including the other experimental reports. Being based on a parametric study by using the model, the amount of the local deformation at the connection are discussed on the bases of the relative strengths of the connections, joint panels, beams and columns.