Learning Forum

[Bob]

In Ansys Mechanical, static analysis of a structure composed of beams is being performed. The ultimate goal is to compare the static analysis results for the same shape of beam-based and shell-based structures. Some of the beam-based structures are as follows.
 
Multiple beams are tied into one joint as follows. Beam-based models perform well in analysis.
Then, the mesh constructed in this way was saved as an STL file and converted into a shell model. The shell-based structure created in this way is as follows.
 
As you can see from the figure, in some parts the shells penetrate each other, and in some parts the shells spread apart. Because of this, the following error occurs when analyzing a shell-based model.
 
How do I solve problems with joints like this?
And when I want to compare Beam and Shell models for the same geometry, is my current approach correct?

[mjmiddle]

The geometry intersecting is not a limiting problem if the bodies are not a in one multibody part. If they are all in the same part and you want them meshed together as node-connected then you have some hard geometry edting to do. And STL can't really be edited well anyway since it's mesh. You would want to create CAD geometry over them to relace them (in SpaceClaim). Then you can handle how the geometry meets at the intersection in the geometry editor.

However, if you don't care about having node-connected mesh at this interface, then it's easy. Just select the edges at the end to connect with a bonded contact or fixed body-body joint. For a bonded contact make sure you set the pinball radius bigger than the gap, and set to MPC type. The MPC type will not have any problems with the intersection.

The pivot warning is probably because you have no connections of any kind for the bodies at this interface.