Seismosoft | Earthquake Engineering Solutions

I have modelling a bridge with various gaps, and I tested the bridge as a simple model and then I thought about adding the expansion joints.
What I'm having is a problem with while modelling the gaps, when I model them using the gap_hk model they give me an unknown error and I won't be able to obtain results, I thought that this is weird so I checked the same properties but using a trl_asm model.
Trilinear Asymmetric Modelling:

trl_asm trl_asm lin_sym lin_sym lin_sym lin_sym 1.0000E+012 0.00 0.00 1.0000E+010 0.00 1.0000E+012 0.00 0.00 -40.00 1.0000E+010 1.0000E+012 0.00 0.00 1.0000E+010 0.00 1.0000E+012 0.00 0.00 -40.00 1.0000E+010 0.001 0.001 0.001 0.001

Gap_hook modelling:
gap_hk gap_hk lin_sym lin_sym lin_sym lin_sym 20.00 1.0000E+012 -20.00 1.0000E+012 20.00 1.0000E+012 -20.00 1.0000E+012 0.001 0.001 0.001 0.001

the trilinear modelling was just fine and didn't give me any errors (I tried the default gap_hk values with no luck)

The gap-hook gap_hk curve has a rather serious effect on the analysis of the structural model, because it effectively blocks the relative deformation between the two nodes of the link element. I noticed that the deformation limits for the trl_asm and the gap_hk curve are different in your example above (deformation = 20 vs 40).
When you say "unknown error" what do you mean?
Seismosoft Support

Try to use the model with Eigenvalue analysis, and then you can see that the model gap_hk gives you an error that's named “unknown error“, I managed to fix that error by changing the model into the trilinear model.

Can you please send the model to support@seismosoft.com ?
Thanks
Seismosoft Support

Unfortunately, I can't because the department won't allow me to.
I might create a demonstration model with the same problem and send it to you.
but please consider this issue till I do.

The only 'unknown error' in the program is an error in eigenvalue analysis. There is no such error related to the gap-hook curve. Without the model, there is not much we can do.
Seismosoft Support

You can recreate the problem while reading the pictures i've sent you privately through your email.
This is how I modelled my bridge and the problem happened between the joints at the top (the expansion joints)

I reiterate that we could not duplicate error. Without the model, there is not much we can do.
Seismosoft Support