Structural Engineering & Statics
where the load goes
Concept

Instantaneous centre — where it appears

2 essays name this object, across 2 fields. What follows is each of them, and the objects they name alongside it.
100 kNe = 150the dashed ring is the group's centroidworst bolt 50.37 kNSix bolts · direct shear 16.67 kN eachelastic vector method

The bolt that carries more than its share

Six bolts, one hundred kilonewtons, and a worst bolt carrying fifty. The load is shared equally and the torque is not, and the second one is invisible on any drawing where the connection is a point.

connections · bolt group centre of masscentre of rigidity1000 kNwest wall500 kN direct+ 39 torsional= 539 kNeast wall500 kN direct+ 39 torsional= 539 kNsouth wall0 kN direct− 19 torsional= 19 kNnorth wall0 kN direct+ 19 torsional= 19 kNcentre of rigidity at x = 15.00 m, y = 9.00 mtorsional radius r = 17.02 m against a plan radius of 10.10 mtorsionally stiff by the usual criterion

The corner that moves most

A lateral force is shared out in proportion to stiffness only if it passes through the centre of rigidity, which is not the centre of the plan and not the centre of mass. The distance between the two is a torque, and the wall that pays for it is the one furthest away and carrying least.

structures · plan torsion

Named alongside it

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

EccentricityAccidental eccentricityBolt groupCentre of rigidityConnectionDiaphragmLateral systemLoad sharingMoment armPlan torsionPlastic redistributionPolar second moment

All concepts