Structural Engineering & Statics
where the load goes
Concept

End plate — where it appears

A plate welded across a beam's end and bolted to its support, carrying moment as a couple between bolt rows in tension and bearing at the compression flange. Its rows are equivalent tee stubs, so each one's capacity is a prying calculation.

Named by 2 essays across one field — each of them below, with the objects they name alongside it.

How a moment crosses a gap. A moment end plate with three bolt rows. The moment is carried as a couple: tension in the rows, compression through bearing at the bottom flange. The plastic distribution reaches 172.8 kN·m and the elastic one 142.29 kN·m, a factor of 1.21 — and the compression at the bottom flange is 540 kN either way, which is the check that gets forgotten because it is not a bolt.

Making a moment cross a gap

A moment is not a thing that can be handed across a joint. It has to be turned into a pair of forces, carried separately, and reassembled — and the whole design is a question of how the tension is shared between bolt rows that are not equally able to take it.

connections · Moment connection Prying against flange thickness. The ratio of bolt force to applied force, for a tee stub carrying 140 kN per bolt, as the flange thickness varies. Prying disappears above 31.91 mm and the flange has become a mechanism below 22.75 mm, where the shaded region begins and the bolt has stopped being the thing that decides.

The thickness that decides who fails

A bolt in a tee stub carries more than the load applied to it, because the flange bends and levers against its own edge. How much more, and whether the bolt or the flange is the thing that gives way, are both decided by one dimension — and the two regimes it separates fail in completely different ways.

connections · Prying

Named alongside it

The objects these essays reach for when they reach for this one.

DuctilityLever armMoment connectionPryingBolt tensionColumn webComponent methodConnectionFree bodyJoint stiffnessPlastic distributionPlastic mechanism

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