I-beam to box–column connection by a vertical plate passing through the column

Box–columns are convenient structural members for moment resisting frames, but providing a proper beam to box–column connection is still under investigation due to the closed shape of box–columns and difficult access to the column inside for developing a reliable load path. To resolve the problem, a new easy-to-fabricate moment connection is proposed for connecting I-beams to box–columns. The connection consists of a vertical plate passing through the column and welded to the column flanges, and beams connected to the plate named the Through Plate. In this paper, the force transfer mechanism of the connection is described and a design method to determine the dimensions of the through plate and other pertinent parts is proposed. An experimental program consisting of two relatively identical cyclically loaded specimens was conducted to evaluate the seismic performance of the connection. The results showed that the specimens reached at least 0.06 rad total story drift before experiencing strength degradation. Moreover, the connection behavior for a range of parameters including member sizes and through plate dimensions were investigated by a verified finite element model to examine the proposed basic design criteria for the connection.