Structural Engineering & Statics
where the load goes
Concept

Rotation capacity — where it appears

3 essays name this object, across one field. What follows is each of them, and the objects they name alongside it.
00.5%1%2%2%050100150200250300350strainstress, N/mm²mild steelcast iron

The property that appears in none of the equations

Ductility is in no design formula on this site. Every method on this site depends on it — and a brittle structure does not merely fail early, it makes the analysis wrong.

materials · ductility 024681000.511.5curvature ÷ curvature at first yieldmoment ÷ moment at first yieldrectangle: 1.50× the yield moment, at 4.1× the yield curvatureI-section: 1.09× the yield moment, at 1.1× the yield curvature

The section that yields from the outside in

A rectangle has half again as much moment in reserve past first yield as its elastic capacity suggests, and an I-section has a seventh. Read as a ranking that gets it backwards — the reserve is bought with curvature, and the rectangle pays four times as much of it.

materials · moment curvature flange outstandk = 0.4318.6 at 23515.2 at 35513.3 at 460quoted: 14ε1.33× the quoted limit, at every gradeweb, in bendingk = 456.8 at 23546.2 at 35540.6 at 460quoted: 42ε1.35× the quoted limit, at every grade0102030405060width ÷ thickness

The section that cannot reach its own strength

A section classification looks like a table of arbitrary numbers. Set a plate's buckling stress equal to the yield stress and the numbers fall out of a formula written three phases ago — larger than the quoted ones by a constant factor, at every grade.

materials · section classification

Named alongside it

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

DuctilityMoment curvatureBrittle fractureEffective widthImperfectionLoad pathLocal bucklingLower bound theoremMoment redistributionNeutral axisPlane sectionsPlastic hinge

All concepts