Load–deformation relations of diaphragm-stiffened connections between H-shaped beams and circular CFT columns

Seismic loads induce local deformations at connections of H-shaped beam to concrete filled circular tubular (circular CFT) columns. Although diaphragms are used for stiffening the connections, a hole is inevitable in the diaphragm for concrete casting, and is likely to result the local deformations. In order to derive a formula to evaluate the amount of the local deformation of a connection of steel beams to circular CFT columns, the elastic-plastic behavior and the deformation capacity of the connections was investigated by an experiment and an analytical model of finite element method (FEM), which was developed by using the experimental results.