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Command line option for iterative solver

Gears Phenom Gears Phenom
Gears Phenom

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


Production: NX10; Development: VB, TCL/TK, FORTRAN; Testing: NX11
Kudos for good posts! And if my post answers your question, please mark it as an "Accepted Solution".
engelke engineering art GmbH, Germany
11 REPLIES

Re: Command line option for iterative solver

Siemens Phenom Siemens Phenom
Siemens Phenom

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

Re: Command line option for iterative solver

Gears Phenom Gears Phenom
Gears Phenom
JimB, I will try it. Thank you. Michael

Production: NX10; Development: VB, TCL/TK, FORTRAN; Testing: NX11
Kudos for good posts! And if my post answers your question, please mark it as an "Accepted Solution".
engelke engineering art GmbH, Germany

Re: Command line option for iterative solver

Gears Phenom Gears Phenom
Gears Phenom
Dear Jim B,
I did re-solve my model with modified command line options as you recommended, thank you.
But now I'm not sure if it did work. - Can I recognize i.g. in log file or f06 file if the solver was the iterative one?
(My f06 file is very large - more than 1GB - and its difficult to open it.)

Best wishes, Michael

Production: NX10; Development: VB, TCL/TK, FORTRAN; Testing: NX11
Kudos for good posts! And if my post answers your question, please mark it as an "Accepted Solution".
engelke engineering art GmbH, Germany

Re: Command line option for iterative solver

Siemens Phenom Siemens Phenom
Siemens Phenom

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.                                      *
*                                                                              *
********************************************************************************

Re: Command line option for iterative solver

Gears Phenom Gears Phenom
Gears Phenom

Dear JimB, now I'm happy, thank you. Best wishes, Michael


Production: NX10; Development: VB, TCL/TK, FORTRAN; Testing: NX11
Kudos for good posts! And if my post answers your question, please mark it as an "Accepted Solution".
engelke engineering art GmbH, Germany

Re: Command line option for iterative solver

Pioneer
Pioneer

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.

Re: Command line option for iterative solver

Siemens Phenom Siemens Phenom
Siemens Phenom

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.

Re: Command line option for iterative solver

Pioneer
Pioneer

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.

Re: Command line option for iterative solver

Siemens Genius Siemens Genius
Siemens Genius

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