ANSYS: Contact problem

pseudorandom

Hi All,
Im new here, please be kind to me :)

I am trying to solve a contact problem (e.g. between a cantilever beam and a fixed block). I am trying to run a Transient analysis but ANSYS wouldnt let me include non-linearity. If I try to input an APDL file with material non-linearity(mu) and contact description (CONTA,TARGE), it just crashes without giving any warnings (or is it a problem with my comp?).

Is it true that non-linear problems cant be solved in time domain? and have to be done in frequency domain? Whats the difference between the two? In my understanding the frequency domain is just a fourier transform of the time domain functions. What equation is it actually solving here? I know one basic equation which it should be solving:
Mx''+Cx'+kx= F(t)

with damping matrix C being a function of eta, alpha and beta damping.

I am not an expert in vibration analysis hence right now a bit confused. Would be great if anyone could suggest me right literature to look at.

Cheers!