Structural Engineering & Statics
where the load goes
Concept

Section shape — where it appears

2 essays name this object, across 2 fields. What follows is each of them, and the objects they name alongside it.
the same, laid flatI = 0.06 × 10⁶1.0× the firstsquareI = 0.75 × 10⁶13.3× the firsttall rectangleI = 10.00 × 10⁶177.8× the firstI-sectionI = 24.29 × 10⁶431.8× the firstevery section here has an area of 3000 — only the shape differsthe bar is the second moment of area, to scale

The same steel in a different shape, and a factor of forty

Four sections of identical area, identical weight and identical cost. The stiffest is dozens of times the stiffest of the flattest, and the only thing that changed was the arrangement.

sections · section shape 00.20.40.60.8100.20.40.60.81moment ÷ plastic momentaxial force ÷ squash loadrectangle: 25.0% of Mp outside the lineI-section: 6.0% of Mp outside the linethe straight-line rule

Two ways to fail, and the curve between them

A column carrying both compression and bending has two capacities and a rule for sharing them out. The rule is a straight line, the truth is a curve, and for a rectangle the straight line gives away a quarter of the plastic moment at half the squash load.

materials · interaction

Named alongside it

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

EccentricityEqual area axisFree bodyHollow sectionI-sectionInteractionLocal bucklingNeutral axisPlastic momentPlastic neutral axisSecond moment of areaShape factor

All concepts