Structural Engineering & Statics
where the load goes
Concept

Saint venants principle — where it appears

The statement that two statically equivalent load systems produce the same stresses away from where they act. Their difference is self-equilibrating, and such a system decays over a distance of the order of the loaded dimension - with thin-walled members in torsion as the exception that travels much further.

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

1200 kN214 kN of tiestruts at 20°0.5 huniform from here onGuyon: 0.25 P (1 − a/h) = 214 kN — the same number, from the same lever armbearing 20.0 N/mm² · once spread 5.7 N/mm²

The force that splits what it pushes on

A prestressing tendon delivers its whole force through a plate a fraction of the section deep. One depth further along the stress is uniform, and the spreading in between requires a transverse tension nobody applied — the force that splits end blocks, and the only number in the design that no equilibrium equation on the member can see.

internal-forces · anchorage zone 00.511.5200.20.40.60.81distance from the loaded end (depths)self-equilibrating remainder ÷ mean stressa point loadspread over h/5split in twoone depthsame resultant, same moment · one per cent left by 1.18 depths

How far a wrong load reaches

Every figure in this collection applies a load as a point, a line or a uniform pressure, and no real load is any of those. The licence is Saint-Venant's, it is usually quoted as a principle, and it is really a statement about a wavelength.

internal-forces · saint venant

Named alongside it

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

Free bodyAiry stress functionAnchorage zoneBearing stressBimomentBurstingConcrete strengthD regionDecay lengthDisturbed regionEigenvalueElasticity

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