No convergence of non linear analysis - slab found on soil with uplift

[Anonymous]

Hi all,

I have a small issue with one of my models. I have a slab on soil with uplift with 2 walls resting on it.

I predefined my soil elasticity kz (100MPa/m) which i put as (100000 kN/m3) in the slab thickness wizard.

Now i need to fixed my horizontal d.o.fs, so i used a planar support with fixed Ux and Uy.

When I run my analysis i get errors about convergence. I have already made the changes I've seen on several posts, that is changing the analysis parameters with matrix updating after each iteration and so on. But no luck at all.

However, if I change my support to an elastic support with a kZ of 100000 kN/m and fixed Ux and Uy, the analysis runs smoothly. But this is not what I need, if I do that, it is as if I am overestimating my kZ or 'doubling' it since I have already specified foundation elasticity parameters in my base slab thickness. (correct me if I'm wrong).

Your advice and comments will be highly appreciated. I am also attaching my model. Thanks 

RSAP 2017 - Windows 10

[Anonymous]

For some reason I'm not being able to attach the model:

can be downloaded from the link below:

https://wetransfer.com/downloads/0a27d83b2faa0c36725914ccb38d449420190316181649/502e9ba8edbd3d3ce2b0...

[Simau · Accepted solution]

Hi @Anonymous 

Set the cases 2 to 5 as auxiliary because they don't act alone without SW

[Anonymous]

Hi Simau,

Thank you. I would like to confirm, when setting the load cases 2 to 5 to auxiliary, results will not be available for them, right? However, the combination results will include the combined results (Is this correct?)?

I am not interested in the individual results anyway, so if the results are included in the combinations, then that works for me. Thanks.

[Simau]

Hi @Anonymous 

I would like to confirm, when setting the load cases 2 to 5 to auxiliary, results will not be available for them, right?

Correct

However, the combination results will include the combined results (Is this correct?)?

Correct

Loads are taken into acount to make combiations then NL analysis is done.

There is ni sense to combine individual NL results

[Anonymous]

Noted. Thank you very much.