Pushover analysis using OpenSeesSP

[andreascj]

Hi,

I am conducting a pushover analysis of a large model using OpenSeesSP. Model runs fine with np = 1 but takes about 10 hours to complete. When I switch to np > 1, gravity analysis completes successfully but then nothing happens afterwards; no errors messages and no sign of completion even after 10 hours. I am using mumps and displacement control and have rigid diaphragm in the model and hence using Transformation constraint handler. One more thing is that in the output folder I get files with .1 and .2 extensions depending on how many processors I specify. I could see some of gravity analysis results in the output file I specified in recorders but no results from any converged pushover analysis (nothing in .1 and .2 files though). I am running model using mpiexec command. Any thoughts on what might be happening?

Thanks.

[fmk]

can you try removing the static analysis and just doing a few steps of the transient to see if that works.

[andreascj]

Hi fmk,

The same story with transient analysis as well.

Thanks.

[andreascj]

Any thoughts fmk? Thanks.

[fmk]

sorry .. missed your reply .. you did remove the gravity analysis and that failed to solve the problem? .. if you did and it didn't i will need to get the code or at least look at it .. are you using NEEShub or is this your own machine . .if NEEShub you can share a session with fmk.

[andreascj]

Hi fmk, sorry, I was doing a transient analysis following gravity. It appears to be working when I only do transient. What does this mean? Thanks.

[fmk]

if the first analysis is working and not the second the problem lies in the Mumps solver (it seems to happen a lot (probably it happens occasionally i only hear about it when there are problems with it)) .. one possible solution is to do a gravity analysis with a different solver and then use Mumps for the time consuming calculations.

[andreascj]

Thanks fmk, that sounds like a good idea but for some reason I cannot use more than 1 processors for other than Mumps. I would like to use Mumps for the for time consuming analysis and some other solver for gravity analysis. Is it possible to do gravity analysis with np = 1 and then do more time consuming analysis with np more than 1?

[fmk]

no.
so mumps fails with np=1 when you do static and then transient. if so i would love to see the script as it might help me see if i can't track down this problem ith mumps.

[andreascj]

Thanks fmk. I will shortly send you the script.

[andreascj]

Hi fmk, to answer your questions:

1. mumps does Not fail with np = 1 when I do static and then transient. The problem starts only for np > 1.
2. With np > 1, I can only do a transient analysis but not the transient following a static analysis.

Would you still like to see my script?
Thanks.