Structural Engineering & Statics
where the load goes
Concept

Dead load — where it appears

The permanent load of the structure and everything fixed to it, and the only load whose magnitude depends on the design it is an input to. The part contributed by the structure itself makes sizing a fixed point, and the share of a member's capacity spent on it is the square of its span as a fraction of a limiting one.

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

2700 kNthe leaf, 900 kN3600 kN on the trunnionno moment, at any angle9 mW·a = 8100 kNm and C·r = 8100 kNm — a product, not a weightinertia 9908 t·m² against 7431 for the leaf alone

Balanced, and four times as heavy

A counterweight cancels a moment about a pivot, and that is the only thing it cancels. The bearing beneath carries both weights, the inertia rises as the square of the radius, and a load that moves cannot be balanced at more than one position at all.

equilibrium · counterweight 11.522.533.54050100150200250300span, relative to the first1×5×16×81×256×moment: the squareload: the first powerdeflection: the fourth

The weight that has to be known before it can be found

Every other load arrives from outside and can be looked up. A structure's own weight depends on how big it is, and how big it is depends on the load — so the first calculation on any project is a fixed point, and the fraction of a member spent carrying itself turns out to be the square of its span as a fraction of a span it can never reach.

equilibrium · dead load

Named alongside it

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

BalanceBearingCentre of gravityCounterweightDeflectionEquilibriumFixed point iterationFree bodyFunicularLever armLimiting spanLoad path

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