Structural Engineering & Statics
where the load goes
Generator

The joint-rigidity generator

Rendered here at the parameters it defaults to, with every essay that calls it — which is the same list as the blast radius of changing it.
The joints are not pins, and this is what that costsA 4-panel Pratt truss solved twice on the same stiffness matrix: once with a moment release at every member end, which is the pin-jointed idealisation, and once with the joints continuous, which is what welding them produces. The axial forces are the same to within a per cent; the bending the second solution adds is worst in member 0, where the bending stress reaches 24.3% of the axial stress. Members are shaded by that ratio.worst secondary bending: 24.3% of the axial stress, in the member markedaxial force there 16.7 kN · end moment 0.20 kNm · slenderness of the member 18the same members, the same loads, the same solver — only the releases differ

1 essay calls joint-rigidity. The drawing above is what it returns with no arguments at all; every call below passes it something, because a placement that passes nothing draws whichever member of the family the generator happens to default to rather than the one its essay argues about.

Where it is called

Changing this generator changes every one of these figures.

worst secondary bending: 24.3% of the axial stress, in the member markedaxial force there 16.7 kN · end moment 0.20 kNm · slenderness of the member 18the same members, the same loads, the same solver — only the releases differ Structural form

The joint that is not a pin

Every truss on this site is analysed as though its joints were frictionless pins. Almost none are. The bending that follows is called secondary, which is a claim about size — and the claim is checkable.

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