Moment Connection: Wednesday's Word(s) Of The Week

Installing a Moment Connection

A moment connection is a rigid connection between parts where rotation is fixed. For example, a purely cantilevered beam only connected at one end (and therefore rigidly connected at that end.) Or, a splice in a glulam arch that is too large to ship intact, but must have a moment connection to re-establish continuity.

Moment Splices are highlighted in this photo

While moment connections are fairly common in steel construction (where parts can be welded to develop the full capacity) and the norm in concrete construction (where members are poured monolithically), they are less common in wood construction. When splices must be used in wood, they should be located to minimize demand.  Moment connection design should be included in initial member sizing, as it will frequently govern the final size.

The finished arena

Moment connection detailing can be a tricky balance of developing strength, minimizing play in the joint, allowing for fit-up tolerances, and accounting for wood shrinkage. 

*Wednesday's Word Of The Week is a feature on Unalam's Wood Times Blog. Each Wednesday our structural engineer, Rik Vandermeulen, will discuss a new term associated with glulam manufacturing. He will do this until we run out of words. If there is a timber or glulam term that you have heard of and want to know more about, let us know in the comments.