This post is probably what you are looking for. I’ve only implemented a static demo problem there, but you can probably figure out how to extend that to the dynamic case.
Mathematically, Hemetian elements are needed to handle the C^1 continuity that Euler-Bernoulli beams require. The library tIGAr you reference utilizes isogeometric analysis (IGA) which uses spline basis functions that have an higher order continuity. This is a classic case of what may be simple in the analytical regime can turn out to be more complicated in the numerical regime.
@kursatyurt : As far as your follow up question on adding point moments and forces, this is not too difficult as long as they are applied to the nodes. In the (near?) future, Pointsource() will be reimplemented in dolfinx, but at the moment you can:
- assemble the system
- locate the DOFs (either using locate_dofs_geometrical() or locate_dofs_topological() )
- directly modify the assembled RHS vector.