Structural Engineering & Statics
where the load goes
Concept

Panel shear — where it appears

The shear crossing one bay of a frame, carried by a diagonal as axial force where there is one and by chord bending where there is not.

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

25.0the cut — three members, three unknowns47.06-52.947.72moments about here kill two of the threesolved without touching any of the other 18 members

Answering one question without solving the rest

A truss of fifty members can be interrogated about one of them. Cut through three, take moments about the point where two of them meet, and the third falls out in a single line.

equilibrium · method of sections 100 kNchord moment 25.0 kNm from the panel shear · axial 200 kN from the global moment6.20 mm against 3.18 mm triangulated — 68% of it is chord bending

The truss with no diagonals

A rectangle without a diagonal is a mechanism, so a Vierendeel girder makes its corners rigid instead. The shear a diagonal would have carried as axial force now travels as bending in the chords, and bending is a far more expensive way to move a force.

structures · vierendeel

Named alongside it

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

Chord forceFree body diagramJoint rigidityLever armLoad pathMechanismMethod of sectionsMoment centreMoment connectionMoment equilibriumPoint of contraflexureSecondary bending

All concepts