General bar element implementation

[Андрей]

Hello, getfem-users.

I would like to implement a 1D element in 3D, which can be cosider all force factors N, Qy, Qz, Mx, My, Mz. I use C++ interface.

For the first i have tried to translate this example https://github.com/getfem-doc/getfem/blob/master/interface/tests/python/demo_truss.py to C++, but I stopped at this point:

md.add_generic_elliptic_brick(mim, "u", "D")

Could you help me to understand а relation between generic_elliptic brick 
and weak form for this case.

Thank you.