Does anyone have some examples of using a U1 user beam element? The documentation on the U1 seems very sparse.
In particular, does the U1 work with different ways of specifying the beam orientation? Can orientation be specified on a per-element basis with the NORMAL definition?
What are the tradeoffs of using a U1 vs. a B32? My understanding is that B32 expands to a bunch of solid elements approximating the beam while U1 uses beam theory to provide the element stiffness matrix.
My inclination is to prefer U1 – am I missing something?
The documentation only describes this element as a 3D Timoshenko beam element (for static linear elastic calculations and small deformations). There’s also a reference to the paper with the formulation of this element and some details regarding keyword syntax. It would be best to run some tests with this element having the same properties as an equivalent B31 element.