Rigid Links and Structural Modifications

Product Support
, , ,
1

I’m trying to model construction stages using result combinations and structural modifications. I encountered the following problem:

If I model the connection using rigid links, the model becomes unstable as soon as I deactivate the concrete slab in fields 2 and 3. However, if I model the connection using rigid beams, everything works fine.

Am I doing something wrong?

Attached is the model where the problem occurs.
Beam.rf6 (1.3 MB)

4

Hi dbesed,
You defined a joint about the local x-axis between the rigid coupling and the attached line.
However, when you deactivate the surface, the upper line remains active and can then rotate freely about its own axis, making the system unstable.
You can define a small spring stiffness about x in the joint; then the calculation should work as expected.

Best regards,
Ulrich Lex