{{Test Problem
name = Connection between shell and frame element |
description = Connection between shell and frame element |
keyword = connection; frame; shell |
program = SAP2000 |
version = na |
status = done |
id = test problems/ok/shell with edge beam}} |
Question
The attached SAP file contains the following:
- Shell element (on the left in the figure below)
- The same shell element with edge beam (on the right in the figure below)
Both shell elements are meshed to 4x4 subelements, but I did not create any connection between the shell element and the edge beam. Therefore, I expected the shell element and the edge beam to deflect independently. However, the edge beam seems to stiffen the shell element, as can be seen from the deflection contours. Is there any explanation for that and for that and how can I model the case when the shell and the edge beam deflect independently?
Answer
When the shells and frames are meshed, they are creating joints at the same location, which then get merged. Even if you only meshed the shells, the frame by default will mesh itself at joints found along its length, unless you turn this behavior off for the frame. This is normally what is desired.
If you don’t want the connection to be made, you should divide the elements explicitly, the select the created joints (which will have been merged,) and select Edit > Point > Disconnect. This will create duplicate joints at the same location. You can then reconnect selected DOF, if desired, using Weld constraints.
Attachments
- [Connection between shell and frame element|^SAP2000 V12.0.0 model.zip] (Zipped SDB File, 0.02 MB)
