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....