Concept
Polar second moment — where it appears
2 essays name this object, across one field. What follows is each of them, and the objects they name alongside it.
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.
The corner that is not the worst point
Check the point furthest from the centroid. It is the standard rule for a weld group under an eccentric load, it is exactly right for some shapes, and for others it misses the peak by sixteen per cent — or picks one of four points it cannot tell apart whose stresses differ by two thirds.
Named alongside it
The objects these essays reach for when they reach for this one.
ConnectionEccentricityTorsionBolt groupCentroidFillet weldInstantaneous centreMoment armPlastic redistributionSuperpositionWeld group