Concept
Integration — where it appears
Accumulating a distributed quantity along a member, which turns load into shear, shear into moment and moment into a deflected shape.
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
The diagram is an integral, and that is why it can be drawn by eye
Load, shear and moment are one function and its two integrals. Once that is seen, the diagrams stop being things to calculate and become things to sketch.
The area of a diagram is a rotation
A deflection is the double integral of a bending moment, and the two constants of integration are the whole difficulty. Mohr's theorems replace them with two pictures — an area, and where that area's centre of gravity sits.
Named alongside it
The objects these essays reach for when they reach for this one.
Moment diagramArea ruleCentroidDeflectionDiscontinuityFirst moment of areaFlexural rigidityGraphic staticsPoint of contraflexureShear diagramSign conventionStiffness