Definition of a Non-linear Support Model

[g.lemon]

I have a design situation where I have a pile pinned at the base and supported by a fender (deformable rubber membrane) at the top. This fender has a non-linear spring shown below:

I have simplified this and input it to robot using the following "function" via the "Definition of non-linear model" tab:

However, I appear to be getting warnings of "non-linear convergance" for some cases, even after changing the calculation settings to save matrix after each iteration and altering the calculation settings to non-linear. I am wondering if this is the appropriate way to model this spring or if anyone suggests another alternative?

[Stephane.kapetanovic]

hi @g.lemon 

For the compressed part, before 70% compression, your curve looks like the SCN 500. For the tension it is less certain (try unidirectionnal supports) but there must be a reason in your modelling ? What it would take is for you to share your model on the forum because the solution is probably to be found inside.

Best regards