Model not converging: SW Load Case, Compression Springs

[Anonymous]

Hi Guys,

As the title suggests my model does not converge when analysing just for self weight when introducing compression only springs on the base slab and or walls. Structure has 2 floors underground.

Note the model runs fine when springs are set to normal (ie tension and compression). The "supports" have been input via the foundation elasticity using the thickness of the panels.

Please see model attached.

[Krzysztof_Wasik · Accepted solution]

Hi @Anonymous 

Model converges for the following calculation parameters.

I would suggest to define weak horizontal elastic support for foundation panels (simulating friction). It will improve convergence (tolerance can be increased to 0.005)

[Anonymous]

Hi Krzysztof,

Thanks for your response and time.

Yup, the model runs now but just for this load case. However as I increase the complexity of load cases/combos I once again run into convergence issues. Good tip on the soil friction, does help, thanks! 

Do you have any suggestions as to why my model fundamentally has convergence issues? What things could I do or avoid to help my analysis converge?

Many thanks

[Krzysztof_Wasik]

Hi @Anonymous 

It is usually model/load related. So I cannot say more without specific cases analysis.

I would suggest calculation load combinations only (simple cases analysis in non linear model makes no sense)

I see that model geometry can be improved