Structural Engineering & Statics
where the load goes
Concept

Moment about an axis — where it appears

The component of a moment along a chosen direction, which is what a torque is and what a bolt group's twist is measured as.

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

56.8 kN13.6 kN49.6 kN120 kNthree legs · rank 3 · determinateΣV, ΣMx and ΣMy all close to 1e-14 kN

Six equations, and the drawing shows three

Ninety essays have taken place on a piece of paper, where equilibrium is three equations and a structure is a diagram. The real object has six, the extra three are the ones nobody writes down, and the difference between three legs and four is not a matter of degree.

equilibrium · three dimensional equilibrium the central axispitch 0.480the couple that stays|R| = 67.08|M| on the axis = 32.20their ratio is the pitchthe ring stands for thecouple, and a couple hasno size and no placexyzP₁P₂

Moving a force, and what it costs

Every free body on this site begins by putting a force somewhere convenient. That move is free along the force's own line, costs a couple across it, and in three dimensions leaves behind something no choice of point can remove.

equilibrium · force couple

Named alongside it

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

Bolt groupDeterminacyEccentricityFree bodyFree body diagramIndeterminacyLever armLine of actionMoment centreMoment equilibriumRankResultant

All concepts