- https://github.com/xcfem/
- https://sites.google.com/site/xcfemanalysis/
- http://www.xcengineering.xyz/
- https://github.com/anaiortega/XCmodels
The author is on FreeCAD forum too. I will point him tho this topic.
How about XC? I have never heard of this FEM software. Since I'm structural engineer too and non of the available solver, neither CalculiX nor Z88 or Elmer does do real beam shell analysis used in structural engineering I'm very interested here too. I had a look at github and the internet page of XC. There is much but not some good overview or video. How do you make pre-processing? What mesh software do you use? Post-processing seams to be done with Paraview? Is it some spare time project or do you are on a university? Lots of questions ...

bernd
structural interface:
https://forum.freecadweb.org/viewtopic.php?f=39&t=27620
links which help to get started:
http://www.xcengineering.xyz/blog_doc/2 ... s_temp.pdf and https://github.com/berndhahnebach/XCmod ... l01/tut.py
https://github.com/xcfem/xc/issues/32
https://github.com/anaiortega/XCmodels/issues/2
https://github.com/anaiortega/XCmodels/issues/4