09-27-2016 09:28 AM
Hello Experts,
often I start NX nastran via command line. I wonder if there is an option to make NX using the iterative solver in SOL101.
I found sys442=1 but I'm not sure if its the the right one.
Nastran help started with "!UGII_BASE_DIR!\NXNASTRAN\bin\nastran64L.exe help all"
did not provide that commad option but it was the difference in LOG-FILE when I started my solution from NX program surface interactively.
Or is it a parameter setting in dat file which has to be activated for iterative solver?
Any suggestions will help, best wishes
Michael
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Solved! Go to Solution.
09-27-2016 10:03 AM
sys442 controls the Solution Monitor for runs launched from NX. It has no effect on the iterative solver.
To activate the global iterative solver, you would set sys216=yes
To activate the element iterative solver, you would set sys216=yes and sys399=yes
09-27-2016 12:32 PM
09-27-2016 02:00 AM
09-30-2016 09:58 AM
If the element iterative solver is used, the .fo6 file will contain the following summary table:
I T E R A T I V E S O L U T I O N S U M M A R Y NUMBER OF EQUATIONS = 1746 NUMBER OF NONZEROS IN STIFFNESS MATRIX = 42642 NUMBER OF NONZEROS IN PRECONDITIONER = 36579 PRECONDITIONER SELECTED = STANDARD NUMBER OF ITERATIONS = 20 CONVERGENCE CRITERIA USED = AREX CONVERGENCE TOLERANCE USED = 1.00E-08 MEMORY AVAILABLE = 8816 MB MEMORY USED IN CG ITERS = 1 MB CG WORKING SET SIZE = 0 MB IF MATRIX OUTOFCORE SCRATCH FILE DISK SPACE = 1 MB MULTIPLY MEGAFLOP RATE = 0 SOLVE MEGAFLOP RATE = 0
If the .f06 is too large to open, you can also look for the following in the .log file:
******************************************************************************** * * * PCGLSS 8.0: Linear Equations Solver * * * *(C) Copyright 1992-2011 Computational Applications and System Integration Inc.* * All rights Reserved. * * * * CASI, 2001 South First Street, Champaign, IL 61820. * * Ph (217)244-7875 * * Fax (217)244-7874 * * * * CASI DOES NOT GUARANTEE THE CORRECTNESS OR USEFULNESS OF THE RESULTS * * OBTAINED USING PCGLSS. CASI IS NOT LIABLE FOR ANY CONCLUSIONS OR ACTIONS * * BASED ON THE RESULTS. IT IS THE RESPONSIBILITY OF THE USER TO CONFIRM THE * * ACCURACY AND USEFULNESS OF THE RESULTS. * * * ********************************************************************************
09-30-2016 10:02 AM
05-04-2018 11:29 AM
My apologies for resurrecting an old thread.
Where would I be able to find more information about the differences between the global iterative solver (sys216) vs the element iterative solver (sys399)?
Are they mutually exclusive?
In order to activate the element iterative solver, is sys216=yes required or will sys399=yes (only) suffice?
Thank you.
05-04-2018 12:25 PM
https://docs.plm.automation.siemens.com/tdoc/nxnastran/12/help/#uid:id511191
Notes for 399: "Note that both ITER = YES and ELEMITER = YES are required to run element iterative solution"
https://docs.plm.automation.siemens.com/tdoc/nxnastran/12/help/#uid:id508246
Remark 2:
- The global iterative solver is requested by specifying ITER=YES on the NASTRAN statement.
- The element iterative solver is requested in SOL 101 by specifying both ELEMITER=YES and ITER=YES on the NASTRAN statement.
05-04-2018 01:19 PM
Thank you.
I am relatively new to using the iterative solvers in NX NASTRAN, so I am still not sure if I understand the difference between the global iterative solver vs. the element iterative solver.
This is the first time that that I've seen where there is a difference and/or a distinction being called out explicitly between the two.
My primary background comes mostly from Ansys and with that, they only have one "class" of iterative solver (which I am assuming in NX NASTRAN terminology - would be the global iterative solver, but I am not sure).
Can you please point me in the direction (perhaps a theory guide) that talks about or documents the difference between what it means "global iterative solver" vs. "element iterative solver"?
Your help is greatly appreciated.
Thank you.
05-04-2018 01:26 PM
You can also find some info about the Nastran iterative solver in our Simcenter Pre/Post documentation:
https://docs.plm.automation.siemens.com/tdoc/nx/12.0.1/nx_help/#uid:id808399