Fatigue and non-lineal analysis

Hi!

I´m running a model with contacts so the analysis must be non-lineal for best results.

Then I must analyze the fatigue but CREO say I must select a previous lineal static analysis to do. So if I need both option. how it´s possible to do that with CREO or it´s not possible at all?

Another issue is, my component has a pretensed bold, so I need a pre-load in the load set added to the main load. But CREO say it´s not possible to use large displacement analysis with pre-loads but I have contacts, so with CREO it´s not possible to do that kind of analysis (non-lineal/large displacement analysis + pre-loads + fatigue).

Thanks for all the answer.

Luis