Mechanical APDL Basic Analysis Guide - Ansys

Chapter 5: Solution
Then run your job and review the output file message to see how much memory you need. If possible, reduce
your -db setting and increase -m so that you can get a sufficient memory block for both assembly and
solution.
Optimize your job and your system After you understand your maximum memory settings and the
memory required for your job, you can try the following suggestions to further optimize your environment.
• For large jobs with memory requirements close to your system's limits, run the solution phase as a batch
job with minimal -db space (usually 64 MB) and force the database memory not to grow (i.e., use a
negative number such as -db -64). Before postprocessing, increase the -db and resume the jobname.db
file and run interactively.
• For nonlinear jobs, try some preliminary runs, restricting the number of cumulative iterations using the
NCNV command. Be sure to use BCSOPTION and review the output for your performance summary.
Based on the performance summary, you can choose to run in-core, optimal out-of-core, or out-of-core.
• Always try to run comfortably within the system memory resources. If you try to use your entire system
maximum memory resources, you will probably require an excessive amount of wall-time to run. A
better option is usually to run in optimal out-of-core mode and use less of your system's total available
memory.
• You should have 2 GB of real memory as a minimum if you will be running large jobs. Set the system
page file for 3 GB, and use the /3GB switch. However, at the /3GB switch to a separate copied line at
the end of the boot.ini file so that you can reboot Windows in normal or /3GB mode.
• Make sure you have 100 GB of disk space to run ANSYS jobs. Do not put everything on your C:\ drive.
Regularly defragment your working directory, and move permanent files to another location after the
job runs.
5.4. Using Special Solution Controls for Certain Types of Structural Analyses
When you are performing certain types of structural analyses, you can take advantage of these special
solution tools:
• Abridged Solution menus, which are available for static, transient (all solution methods), modal, and
buckling analyses. See Using Abridged Solution Menus (p. 106).
• The Solution Controls dialog box, which is available for static and transient (full solution method only)
analyses. See Using the Solution Controls Dialog Box (p. 107).
5.4.1. Using Abridged Solution Menus
If you are using the GUI to perform a structural static, transient, modal, or buckling analysis, you have the
choice of using abridged or unabridged Solution menus:
• Unabridged Solution menus list all solution options, regardless of whether it is recommended, or even
possible, for you to use them in the current analysis. (If it is not possible for you to use an option in the
current analysis, the option is listed but is grayed out.)
• Abridged Solution menus are simpler. They list only those options that apply to the type of analysis
that you are performing. For example, if you are performing a static analysis, the Modal Cyclic Sym
option does not appear on the abridged Solution menu. Only those options that are valid and/or recommended
for the current analysis type appear.
If you are performing a structural analysis, the abridged Solution menu appears by default when you enter
the solution processor (Main Menu> Solution).
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