Energy dissipation — where it appears
Named by 2 essays across one field — each of them below, with the objects they name alongside it.
Also named here as hysteresis — the same set of essays touches all of them, so they are one junction rather than several.
The only thing that stops it
Drive a structure at its own frequency and the amplitude grows without limit unless something takes energy out. What takes it out is damping, and damping is the one structural property that is never designed, never drawn, and never known until the thing is built.
The earthquake asks for a displacement
A structure a quarter as strong as the elastic demand does not deflect four times as far. It deflects almost exactly as far, yields on the way, and survives — which is why no ordinary building is designed for the force an earthquake would apply if it stayed elastic.
Named alongside it
The objects these essays reach for when they reach for this one.
HysteresisBehaviour factorCapacity designDampingDamping ratioDuctilityEqual displacement ruleFree vibrationLogarithmic decrementPlastic hingeResidual displacementResonance