Concept

Column web — where it appears

The plate of a column section between its flanges, which a beam framing into it loads in shear, in compression and in bending all at once. It is frequently the weakest component of a moment connection and the one a stiffener is added to strengthen.

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

A joint is springs in series. The five components of an end-plate joint, with each bar the flexibility it contributes. The column flange in bending is 39.62% of the total on its own, and doubling its stiffness raises the joint's by a factor of 1.25 — while doubling the stiffest component buys 1.05. The joint's rotational stiffness is 25227.71 kN·m per radian.

A joint made of springs in series

A connection's stiffness is not a property of the connection. It is the series combination of the flexibilities of everything the force passes through — so the softest component decides, and stiffening any of the others changes almost nothing.

connections · Component method

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

Named alongside it

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

Connection Lever arm Prying Component method Ductility End plate Joint stiffness Moment connection Plastic distribution Rotational spring Series stiffness

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