• Registered: 2021-01-13
  • Posts: 1

Topic: CCBeamNL element

Hi,

we would like to use the "CCBeamNL" element instead of the "CCIsoBeamBrick12_3D" element because we do not need all 6 components of 3D strains and stress vectors.
We didn't find an example where this element is used.
Does anybody know the input code therefore?

We tried it the same way as for CCIsoBeamBrick12_3D with:

ELEMENT TYPE ID 1 Name "Beam_Concrete" TYPE "CCBeamNL" LINEAR ;
ELEMENT GROUP ID 1 TYPE 1 MATERIAL 1 GEOMETRY  1
ELEMENT INCIDENCES
...

If we start the calculation we got the following warnings:
Warning: Attempt to constrain slave/use master non-active or zero dof: 1 of node: 81, load case: 10001, dof BC: 2, LHS BC id: 37; constraint  ignored.
Warning: Redundant (needless) LHS BCs detected for the following u(node_id,dof_id):
[0*u(105,2)=0] ,[0*u(103,2)=0] ,[0*u(113,6)=0] ,[0*u(111,6)=0] ,[0*u(110,6)=0] ,[0*u(109,6)=0] ;
they will be ignored.

Best regards & thanks,
Christina

Quote Post 1

  • Registered: 2020-02-21
  • Posts: 4

Re: CCBeamNL element

Dear Christina,

The CCBeamNL element is not supported in the current version of ATENA. Can you specify what you are modelling and what is the purpose of using the beam elements? If possible in your model, I recommend you to use 1D beam elements.

Quote Post 2

  • Registered: 2017-08-30
  • Posts: 6

Re: CCBeamNL element

Hello Gabriela

I am actually working together with christina in this project.

We followed your advice and used the 1D-Beam element. It seems to work fine.

The reason we initially tried to use the "volumetric" Beam element was that for our system it seemed to be more comfortable for the mesh building.  It would have been nice to use the 3D beam because the coupling to other elements would have been a little easier and in the theory manual it was described that a real "beam kinematic" is used (not like with the isobeambrick where all strain components are used according to the manual).

However it is a bit of speacial case with us:
We work on a parametric study we do the "meshing" on our own and generate every node and element by hand with the help of another FE-Software where you can easily code the meshing routine and then kind of translate it to atena. In our special case this is very convenient for us as we just need to build the model once and we use the results of both programs to compare.

But now its all working - thank you for your help

Quote Post 3