Structural Engineering & Statics
where the load goes
Concept

Weld group — where it appears

A set of weld runs treated as one section resisting a force and a moment about their own centroid. The throat stress is a distribution round the group rather than a total divided by a length, and the peak is at the greatest radius from the centroid.

Named by 2 essays across one field — each of them below, with the objects they name alongside it.

100 kNpeak 0.88Two points at maximum radiusthe radius rule finds the peak hereequal radius, stresses differ ×1

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.

connections · weld group 800 kN1.161.050.970.920.890.890.920.971.051.16an equal share675 mm = 33.8 dworst bolt 93 kN against a nominal 80 kN

The joint that has to be as good as the member

A splice exists because members come in lengths and structures do not. It has to deliver the same force, at the same stiffness, in the same distribution across the section, through a discontinuity — and each of those three requirements is met by a different feature of the detail, with the third one usually left to look after itself.

connections · splice

Named alongside it

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

ConnectionBolt groupCentroidContinuityContraflexureDuctilityEccentricityFillet weldJoint stiffnessLoad pathLoad sharingMoment rotation

All concepts