A moment connection is designed to resist rotation at the joint - most hollow section connections, unlike open section connections, will not allow a great deal of flexibility and will rely on the rotation capacity of the connection components of the incoming beam. These connections are defined specifically as Moment Resisting which means the load transference between the beam and column takes it's path through the sidewall of the hollow section columns.
The following connection examples represent some of the more common connection types - they are not exhaustive and will be expanded to accommodate more options.
Hollow Section to Hollow Section
Fig. 1 illustrates a typical side plate connection. The side plate may be shop-welded (as shown) or blind bolted to the column while the incoming beam has angle cleats welded to the top and bottom on the profile - match drilled and site bolted.
Fig. 2 shows a typical cleat connection where the cleats are welded to both the column and beam - the joint is then site-bolted.
Both of these options use through bolts
The next examples show moment resisting End-Plate connections.
Fig. 3 illustrates a typical fabricated connection where wrap-around plates are shop fitted and welded to the column - the end-plate is then shop-welded to the edges of the plates. The protruding distance should be sufficient to allow access for tightening the bolts. The incoming beam is fitted with an end-plate, match drilled to suit.
The bolts should not be positioned beyond the corners of the profile, instead they should be positioned near the RHS walls, where the tension load acts, not at
the plate corners.
Fig. 4 shows a connection where the end-plate is fixed directly to the supporting column