3D + 2D + 1D Reinforced Concrete FEM simulation and Lightning Simulation

[JTM2020HYO]

1)

is possible to use Elmer to simulate 3D as concrete + 2D wall + 1D Reinforcement Rebar at the same time?

2)

is possible to create a Lightning and Grounding SImulation and Analysis?

[kevinarden]

It is possible to combine 3D, 2D, and 1D elements in a structural analysis and assign the appropriate material properties to each element. The type of analysis would be limited to linear, geometric non-linear, eigenvalue, vibration, stability, etc. Elmer does not have a built in material non-linear capability but allows the inclusion of your own material models via user subroutines.

[raback]

To specify, I would think that the current features are limited in joining shells to solids at their edge, and beams to shells at their end. So analysis where lower dimensional entity is merged into the higher dimensional is not currently supported.

I think that something could be done rather straight-forward by indentifying the same degrees of freedom and summing up (or eliminating) the related matrix rows. Still the coding & testing task would be measured in days rather than minutes.

-Peter

[kevinarden]

Mika did some work last year to integrate beams into shells with shellsolver.

viewtopic.php?f=18&t=7058

[raback]

Ok, I take back my words Thanx Kevin! I also appreciate the nice example.

So it seems you can merge 2D & 1D but not currently 3D & 2D except when joined at the shell boundary. '

[kevinarden]

It at least solved without errors and took into account the elements. I built a solid element mesh, created 2D elements on one side, and embedded 1D elements in the interior to represent rebar. I hand to manually edit the mesh files to create the mesh because the Elmer tools turn lower dimension elements into boundary elements. I would have to develop a test case to see if it is an accurate solution but StressSolver does provide a solution. It would be nice if there was some way to flag ElmerGrid to maintain lower dimensional elements as structural, not boundary,

rebar.png

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mesh.png

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rebar.zip

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[kevinarden]

It won't work with StressSolver, you can not assign thicknesses to 2D elements. you need ShellSolver for that. Since ShellSolver has integrated beam elements, it would have to be modified to include solid elements. Then it would be a general solid mechanics solver.