Tri-element geometric stiffness

[astro808]

Hi everybody,

I am trying to write a small script to determine the total geometric stiffness matrix of a FE model containing only triangular plate elements with bending stiffness similar to the NASTRAN TRIA3 elements. I found several definitions of the geometric stiffness matrix (3x3) of such elements without bending but none with bending (18x18, 3dof will be zero but need the full matrix to transform to global CS for assembly). Are there any sources that give this stiffness matrix or a detailed outline of the derivation?

 

[MiketheEngineer]

Above my pay grade!!

 

[JoshPlumSE]

I can't help you too much. But, there is another forum for "Finite Elemnent Analysis engineering" that gets into more esoteric topics like this. You might try that forum instead.