Preffered analysis options

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ospinag
Posts: 23
Joined: Fri Jul 30, 2010 7:51 am
Location: University of South Carolina

Preffered analysis options

Post by ospinag »

Hi everyone,

I have a model with +4100 nodes, containing elastic beam elements and shell MITC4 elements. I'm trying to make a time history analysis but it's taking very long, which seems weird to me. I'm using the following analysis options:

integrator Newmark 0.5 0.25;
test EnergyIncr 1.0e-12 10 0
algorithm Newton
numberer RCM
constraints Transformation
system ProfileSPD
analysis Transient;
analyze 159 0.0175

can somebody make a suggestion of what options to change to make it faster? Currently is has taken almost 24hrs running in the Neeshub site, and the analysis has not finished.

Thanks!
vesna
Posts: 3033
Joined: Tue May 23, 2006 11:23 am
Location: UC Berkeley

Re: Preffered analysis options

Post by vesna »

To me it looks like the analysis is hanging somewhere (it got stuck).

For large models use Sparse solvers (e.g. UmfPack). Your tolerance may be too low. I would not go lower than 1e-8.

make use of "puts" command to check the progress of your analysis. Do your anlaysis in a loop and after each step of analysis output the time step.
ospinag
Posts: 23
Joined: Fri Jul 30, 2010 7:51 am
Location: University of South Carolina

Re: Preffered analysis options

Post by ospinag »

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Last edited by ospinag on Mon Jul 09, 2012 12:03 am, edited 1 time in total.
ospinag
Posts: 23
Joined: Fri Jul 30, 2010 7:51 am
Location: University of South Carolina

Re: Preffered analysis options

Post by ospinag »

vesna wrote:
> To me it looks like the analysis is hanging somewhere (it got stuck).
>
> For large models use Sparse solvers (e.g. UmfPack). Your tolerance may be
> too low. I would not go lower than 1e-8.
>
> make use of "puts" command to check the progress of your
> analysis. Do your anlaysis in a loop and after each step of analysis output
> the time step.

Thanks!
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