Partially restrained composite beam–girder connections

Abstract

Beams in a typical steel framed floor system are assumed to have rotationally pinned supports for the purpose of design. In reality, the connections between beams and girders are not rotationally pinned. The connection rotational restraint is characterized by the moment–rotation behavior. This restraint may be a beneficial attribute that can be considered in design. However, a method for approximating the moment–rotation behavior of the beam–girder connection is required before the beneficial effects of the true connection rotational restraint can be considered in design. An experimental and analytical study of the moment–rotation behavior of composite beam–girder connections is presented in this paper. Eight full-scale connections (four cruciform test setups) were tested experimentally. This experimental data was used to verify a component model that is used to approximate the moment–rotation behavior of the connections. The component model was then used to analyze a variety of connection parameter combinations. The results from this analysis were used to develop a simpler method of approximating the moment–rotation behavior of composite beam–girder connections. Although beam–girder connections were the focus of the study reported in this paper, much of the material described is applicable to composite and bare steel PR frame connections.