Critical load
Strong enough and still falls over
A column can fail at a fraction of the load its material could carry, by going sideways. Buckling is a failure of stability rather than of strength, and it is decided by geometry.
The column that was never straight
Euler's load is the load at which a perfectly straight column becomes indifferent to being bent. No column is perfectly straight, so no column ever reaches it — and the load it never reaches can still be measured.
The brace that need not be strong
A brace holding a column at mid-height carries almost no force. What it has to be is stiff — and the stiffness required is exact, large, and reached at a knee past which more buys nothing at all.
The water that will not run off
A flat roof deflects, the deflection makes room for water, the water deepens the deflection. It is the same equation as a buckling column, with rain in place of the axial load.
Named alongside it
The objects these essays reach for when they reach for this one.
ImperfectionAmplification factorEffective lengthEuler bucklingResidual stressStiffnessBifurcationBracingBuckled mode shapeDeflection limitEigenvalueLateral restraint