Behavior of Single Plate Shear Connections with Rigid and Flexible Supports

Abstract

Single plate framing connections are a type of shear connection which must sustain both shear and moment transferred from the supported beam. Commonly found in both rigid (beam-to-column flange) and flexible (beam-to-girder web) configurations, the single plate connection has proven to be both economical and easy to erect. A specified design method for single plate connections is presented in the AISC LRFD 3rd Edition Manual (AISC 2003). The design method calculates for associated limit states or failure modes and accounts for eccentric shear created by the moment sustained by the connection. Overly conservative tabulated design strengths, which lead to heavier, more costly, connections, has emphasized the need for research to improve upon the current design procedure. The focus of this research is to address the conservative nature of the currently specified design method.

To create a basis for comparison to theoretically calculated design strengths, a total of ten full-scale tests were conducted. Tests incorporated both rigid and flexible support conditions, both standard and short-slotted bolt holes, and connections consisting of various numbers of bolts. Differing from previous research efforts, this series of research incorporated a simulated slab restraint with flexible supported tests. In order to evaluate experimental results and remove unknowns, supplemental tests were conducted to determine the material properties of components used in testing.

Major goals accomplished in this research included the investigation of connection limit states and component behavior. Focus was given to qualifying rotational behavior and quantifying the extent that eccentric shear is experienced by the connection as this is felt to be a potential cause of the overly conservative tabulated design values. In addition, comparisons of the AISC design method were made to design methods proposed by other researchers and design methods specified in other countries. All investigations focused upon improving the currently accepted AISC design procedure for single plate framing connections.