Space frame — where it appears
Named by 2 essays across 2 fields — each of them below, with the objects they name alongside it.
Three equations at every joint
A plane truss is determinate when m + r = 2j. A space frame needs 3j, and that one changed digit is why a cube of twelve bars is six mechanisms short while looking perfectly solid — and why every three-dimensional frame ever built is made of triangles in several planes at once.
The most dangerous day is before it is finished
A structure is analysed once, complete, with every restraint present. It spends weeks in states nobody drew — a beam landed with no deck on it holds 17% of the moment its section is worth, a frame not yet braced buckles at a third of the load it will, and a bolt not yet tightened is a pin where the analysis assumed a fixity.
Named alongside it
The objects these essays reach for when they reach for this one.
Load pathBracingConstruction sequenceDouble layer gridEffective lengthEquilibrium matrixErection stabilityJoint stiffnessLateral restraintLateral torsional bucklingLoad sharingMatrix rank