Structural Engineering & Statics
where the load goes
Concept

Prying — where it appears

3 essays name this object, across one field. What follows is each of them, and the objects they name alongside it.
100 kN appliedbolt 150.63 kNprying 50.63 kNm = 45n = 40flange 20 mm · one-hingebolt force is 1.51 times the applied load

The force the bolt never saw applied

Pull a tee stub with a hundred kilonewtons and its bolt carries a hundred and fifty. The extra comes from the flange bending and pressing its own edge against the thing it is bolted to, and no free body of the connection as a point contains it.

connections · prying flexibility contributed by each componentthey add, so the softest dominates — Sj = 25227.71 kN·m/radwhat doubling it buyscolumn web in shear21.89%×1.12column web in compression11.55%×1.06column flange in bending39.62%×1.25end plate in bending18.09%×1.1bolts in tension8.85%×1.05

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 180 kNrow 1 · 420 mm180 kNrow 2 · 340 mm180 kNrow 3 · 200 mm540 kN compressionPlastic distribution — M = 172.8 kN·mthe other distribution is drawn faintly: 1.21× between them

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.

ConnectionLever armColumn webBolt tensionCollapse mechanismComponent methodDuctilityEnd plateFlangeJoint stiffnessMoment armMoment connection

All concepts