Buckling of cylindrical Shell problem

Hello KARAMBA 3D community,
Could someone help me please with the following problems in order to continue my modelling for bulking of cylindrical Shell problem? Unfortunately, only KARAMBA 3D users can open the file and see all components.

  1. How can I apply the support on the bottom plate?
  2. There is an issue with the Point Load on the middle of the plate. “Solution exception:Could not find node at (3/2.04692546598694E-16/6.825) where point-load number 0 is attached.”
  3. Finally, how can I make the cylinder as shell with thickness of 0.20 cm for example? My method does not work.
    Here is the a screen shot of the model.
    grafik
    Here is the grasshopper file.
    BulkExpermeint_CylindericalShell 2019.Nov23…gh (40.3 KB)

Many thanks in advance.
Kind regards,
Ihab

Duplicate thread alert! Would have been better to continue that thread…

Here is your walled cylinder, 0.2 units thick. Note, however, that it intersects the bottom plate because they both use the same base point.


BulkExpermeint_Cylinder_2019Nov23d.gh (28.8 KB)

A few small changes fixed the plate/cylinder overlap problem (version ‘23e’). The slider now specifies ''Height OA" (Height Overall) and the top plate, cylinder base and length are adjusted accordingly.


BulkExpermeint_Cylinder_2019Nov23e.gh (31.4 KB)

1 Like

Hi @ihabfsaid,

the point that you use for the support is not a point on your actual geometry that is brought into Karamba. If you want to use the mid point of the plate, then you should also put the plate into the Karamba model. However then you would most likely want to use all points of the bottom plate mesh for your supports.

Hello Matthew,
Could you please tell me how exactly I can apply the Load and support in my Modell? I failed at defining position of the Load on the middle of the top plate and at defining the position of the support on the bottom plate

Moreover, is my way for the defining of the Elements of the Model as shell elements correct?

Here is the modified file in grasshopper:
BulkExpermeint_Cylinder_2019Nov25.gh (37.4 KB)

I am looking forward to your answering and many thanks in advance.

Kind regards,
Ihab

Hi @ihabfsaid,

You have approached the setup wrong. You need to define only the shell axis for the analysis and define the thickness using a cross section. Then you can use the MeshBreps component to convert the surface axis to meshes which will have the necessary intersection points for Karamba shells.

By using the Model View component with the Node Tags turned on you can see which points are defined as your load and support position.

Well it will be super nice of you if you can upload your file solving this problem from all views, because I am getting stuck everywhere. Thanks in advance

Hi @ihabfsaid, i have not updated your file. However you simply need to model the axes of your surfaces and not the full volume of your plates.

hi @ihabfsaid

You had several problems in your defenition.
The plates were not connected to each other, the bottom plate and the top plate were not well meshed.
You only had a support on your baseplate …

So in my model attched.

I only define plates with a mesh in 2D, the thickness is defined on the cross sections
I use the Karamba brep mesh components to ensure connections between plate / cylinder (and add specifics points on plates meshs)
I apply simple support to all the nodes that make up the bottom plate and apply a surface load on the top plate.


BulkExpermeint_Cylinder_2019Nov25 JAC.gh (59.5 KB)
Regards