If I want to construct myself a geometric stiffness matrix induced by a pre constraint with finite element modeling

[vanji1]

Dear all

I would like to know how to generate a geometric stiffness matrix induced by a preconstraint. Once I have the geometric strain tensor, How do I proceed for implementing this using Voight notations ? In fact I find approximation formulations in the literature.

Sibcerely yours,

Evangéline