How to model non-linear springs connected to rigid beam

Hi I am trying to model some piles along a line, all connected with a beam. The beam is subjected to a force in an arbitrary direction and location on the beam.

I have a work law that describes the piles displacement depending on the force it is subjected to.
Problem is when I try to model this in two dimensions I get an incorrect result - (I tried using a node with a NL-spring in global x and Y direction but this does not give me the same resulting displacement as a node with one spring acting in the same direction as the force).
I want the spring to have the same stiffness independent of the direction of the force.

Any ideas on how to model this problem are very welcome :slight_smile:

Example of setup: