Spring Stiffness Definition

Hello,

I try to define a spring using "special spring" in a static analysis.

My problem is the coupling of the translation and rotation / force and moments. The entries of the matrix are KTXX, KTXY, .... [N].

Does anybody know how to interpret these values?

From my point of view, the term KTXY connects the rotation in X to the translation in Y. In other words, KTXY creates a Moment if a displacement in Y direction is applied. But even if i put in the correct ratio ( KTXY = MX / UY ), the results are not correct.

I've double checked the units, and they fit.

So my questions are:

1) Are my assumptions correct? Is the coupling term the ratio between the resulting Moment and the Displacement?

2) How does the "special spring" matrice work? I suspect something like this....

Translation(3x3) , Zeros(3x3)

Coupling(3x3) , Rotation(3x3)

I hope somebody is able to help.

Thank you!