Structural Engineering & Statics
where the load goes
Generator

The prying-curve generator

Rendered here at the parameters it defaults to, with every essay that calls it — which is the same list as the blast radius of changing it.
Prying against flange thicknessThe ratio of bolt force to applied force, for a tee stub carrying 100 kN per bolt, as the flange thickness varies. Prying disappears above 26.97 mm and the flange has become a mechanism below 19.13 mm, where the shaded region begins and the bolt has stopped being the thing that decides.05101520253011.21.41.6flange thickness, mmbolt force ÷ applied forceno prying above 26.97 mmflange is a mechanism

2 essays call prying-curve. The drawing above is what it returns with no arguments at all; every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the one its essay argues about.

Where it is called

Changing this generator changes every one of these figures.

100 kN appliedbolt 150.63 kNprying 50.63 kNm = 45n = 40flange 20 mm · one-hingebolt force is 1.51 times the applied load Connections

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.

 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 Connections

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.

The library, page 2 of 4 — where prying-curve sits