Theory Regarding Geometrically Nonlinear 2D Elements

[dyrisk]

Hello to all,

I am trying to understand the code in FEAP for modelling a static, geometrically nonlinear, 2D element.
I am currently going through sld2d.f and slowly going through all other internal subroutines it calls, however, I wanted to know if there are any available reference(s) with details on the theory behind the FEM formulation used for creating these files.

Thanks in advance!

[Prof. S. Govindjee]

Have a look at the FEAP Theory Manual http://feap.berkeley.edu/wiki/index.php?title=Manuals.
Also if you are interest in nonlinear (finite deformation) elements you should be looking, for example, at fld2d1.f.

[Prof. R.L. Taylor]

Element routines starting with “sld” are small deformation and those with “fld” are finite deformation