Load-Deformation Relation Models for Local Deformations in Diaphragm-Stiffened Connections of H-Shaped Steel Beams to Rectangular CFT Columns

Abstract

This paper presents load-deformation relation models for connections of H-shaped steel beams to concrete filled rectangular tubular columns (CFRT columns) in moment resistant frames. Although the column is usually stiffened by a steel plate diaphragm at the connection, a reduction of diaphragm rigidity, which is caused by a concrete casting hole in the diaphragm, leads to a fairly large local deformation at the beam flange joint. A simple model of the relation of beam flange load and local deformation is proposed for typical connection types of the external diaphragm, the inner diaphragm, and the inner diaphragm with extended flanges. The model is compared with an experimental data base and a FEM numerical data base.