Structural Engineering & Statics
where the load goes
Concept

Post buckling — where it appears

What a structure does past its critical load, whose slope decides whether an imperfection costs a few per cent or most of the capacity.

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

1002003004005006007000200400600plate width (mm)slender beyond 370 mmyieldcritical stress — inverse square in the widthwhat the plate actually delivers, over its full width

The plate that ripples, and the width that is left

A wide thin plate in compression buckles at a stress that has nothing to do with the strength of the material. It then goes on carrying load — the middle drops out, and the edges work harder.

stability · plate buckling stable symmetric — a columnan imperfection is a nuisancecritical89%unstable symmetric — a shellan imperfection is a demolitioncritical77%asymmetric — a frameand it matters which waycritical

A third of what the theory promised

A column with a small crookedness reaches almost its full Euler load. A cylinder with the same relative crookedness reaches a third of its classical one, and the theory is not wrong — what separates them is the slope of the path just past the critical load, which no calculation of the critical load itself can see.

stability · imperfection sensitivity

Named alongside it

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

BifurcationBucklingEffective widthEquilibrium pathImperfection sensitivityKnockdown factorPlate bucklingSection classificationShell bucklingSlendernessStabilityWidth to thickness

All concepts