Structural Engineering & Statics
where the load goes
Concept

Hogging and sagging

2 essays name this object, across one field. What follows is each of them, and the objects they name alongside it.

Also named here as point of contraflexure — the same set of essays touches all of them, so they are one junction rather than several.

00.050.10.150.20.250.30.3501020304050overhang, as a fraction of the spanbest at 21% — peak 8.8sagging, mid-spanhogging, over the supportmoving the supports in by a third of the way halves the worst moment

Where to put the supports, which is not at the ends

Moving the supports of a uniformly loaded beam inward by about a fifth of its length halves the worst bending moment. The load has not changed and nor has the beam.

internal-forces · support layout moment19.6 sagging24.5 hogging30.6 if the spans were simplereactions 14.0 38.5 38.5 14.0 — the inner supports carry far more than a sharethe continuous case needed stiffness; the comparison did not

The moment over the support, and what it buys

Run a beam over its supports instead of stopping at each one, and the mid-span moment falls by a third while a new moment appears where there was none. Nothing was added but continuity.

internal-forces · continuity

Named alongside it

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

ContinuityMoment envelopePoint of contraflexureMoment redistributionOptimisationOverhangPattern loadingReaction distributionReactionsStiffness

All concepts