Structural resistance of longitudinal double plates-to-RHS connections

The purpose of the study reported herein is to investigate the behavior of longitudinal double plates-to-RHS connections in a T-configuration. A total of seven specimens (5 for double-plate type, 2 for single-plate type) were tested under compression. The main experimental parameters were the width ratio of the branch plate to the chord ( β ) and the type (or number) of branch plates. Test results showed that the value of β and thereby the strength of the double-plate type specimens increased due to the space between the plates. Furthermore, a combined failure of chord flange yielding and chord web buckling, which was not generally observed in longitudinal single plate-to-RHS connections, was observed in one of the double-plate specimens. A yield line analysis was also performed for different locations of plastic hinges, considering the corner radius of the HSS chord, as well as the welds for the plates. The strengths based on the proposed yield line model showed good agreement with the experimental results when the plastic hinges were assumed to be located at the web of the HSS chord adjacent to the corner radius, and at the toe of the welds.