Hi Dan (@daniel11)!
You can take welding into consideration by using bonded contacts. A “Weld Feature” is not yet implemented into the SimScale platform.
If you like, you can put your request into the “Vote for Features!” category. I am sure there are some users who are also interested in the welding feature.
As an example for a frame frequency analysis,you could have a look at Session 2 of the Makers Workshop.
Hope that helps!
Best,
Jousef