Structural Engineering & Statics
where the load goes
Concept

Fully stressed design — where it appears

Proportioning every member so that it reaches its permitted stress exactly, which is the natural objective when strength is the only constraint. It is not the minimum-weight design once buckling is included, because a strut's area depends on its length as well as on its force.

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

30 kNwhat it can carrywhat it carriesworst at 3.00 mfree endroot79% used at the governing station · 70% at the root

The section that changes along the span

A prismatic beam is checked where the moment is largest, and everyone knows where that is. A tapered one is not, because the capacity is moving too — and for a cantilever with a load at its tip the governing station is exactly where the depth has doubled, with no length, no load and no material in the answer.

sections · tapered member the split, at 5.1 mvolume 0.100 × 10⁹ mm³ against 0.204 for a fan from the base3 of 3 members sized by buckling

The tree that strength does not ask for

A branching column carries a roof on many points and reaches the ground on one. Size every member by its stress and the optimum tree turns out to have no trunk at all — the best answer is a fan of straight struts from the base. Put buckling in and the trunk appears, at 57 per cent of the height.

structures · branching structure

Named alongside it

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

Bending momentBranching structureBucklingConcurrencyDeflectionEquilibriumForm findingFree bodyFunicularHaunchJointLoad path

All concepts