Timber — where it appears
Named by 3 essays across 2 fields — each of them below, with the objects they name alongside it.
The material that has a direction
Every material in this collection so far has had one modulus and one strength. Timber has three of each, differing by more than an order of magnitude, and the consequence is not a correction to steel design — it is a different set of checks with a different one governing.
The smallest of six failures
Everything else in this collection that fails does so in one way at a time. A dowel through timber does not — the wood can crush while the steel stays straight, or one plastic hinge can form in it, or two — and the capacity is the smallest of the six, which is the kinematic theorem of plasticity applied to a joint rather than to a frame.
The ranking belongs to the load case
Every table of material properties ever printed ranks by strength, and every one of them answers a question nobody asked. What a structure wants is the least mass for a stated performance, and the combination of properties that gives it changes with the shape of the member — so timber beats steel four to one as a beam and loses to it as a tie, without either material changing.
Named alongside it
The objects these essays reach for when they reach for this one.
AnisotropyBearingElastic modulusGrainBound theoremsCarbon fibreCollapse loadConnection designCostDensityDesignDimensional analysis