Structural Engineering & Statics
where the load goes
Concept

Superposition — where it appears

3 essays name this object, across 2 fields. What follows is each of them, and the objects they name alongside it.
20 at 2δ at B = 93.33320 at 6δ at A = 93.334the shapes have nothing in commonand the two readings agree to 1e-14which is why an influence line can be measured by pushing the structure where it is easy to push

The theorem that swaps the question round

Push here and measure there; push there and measure here. The two readings are identical, for every elastic structure, whatever its shape — and that fact turns an influence line into something a model can be asked for directly.

deflection · reciprocity -0.6%-0.4%-0.2%0.2%0.4%0.6%-300-200-100100200300strainstress, N/mm²0.469% of the strain never came back

What is left when the load comes off

Unload a section that has yielded and it does not return to nothing. It returns to a self-equilibrating stress field it did not have before, a permanent set, and an elastic range wider than the one it started with.

materials · unloading 1 d10 d100 d2.7 yr27 yr0246810time since the strain was imposedstress, N/mm²E × strain: 9.6tensile strength: 3.5what is left: 2.32the one-line shortcut at χ = 0.8: 3.31

The strain that was imposed, and the stress that leaked away

Multiply a restrained shrinkage strain by the modulus and the answer is three times the tensile strength — which predicts that every restrained concrete member ever cast has cracked. Most have not, and the reason is that the material creeps while it is being stressed.

materials · relaxation

Named alongside it

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

PrestressAgeing coefficientAutofrettageBauschinger effectCrackingCreepFlexibilityImposed deformationInfluence lineKinematic hardeningMüller-Breslau's principlePermanent set

All concepts