Chapter 20: File Management and FilesThe ANSYS program uses many permanent and temporary files during an analysis.. File Management Overview The ANSYS program uses files extensively for
Trang 1Following is an explanation of the JavaScript code:
<script LANGUAGE="JavaScript1.2" SRC="ansysAnimations.js"> </script>
Loads the ansysAnimations.js file to provide the animation sequences You must include this line
of code at least once in your HTML document and before calling the animName function Typically, thisline appears in the <HEAD> section of an HTML document
animTime
The time delay (in milliseconds) between each display of an individual image in the animation sequence.This value is limited by the capabilities of your computer hardware; therefore, a value lower than 500typically has little effect on the animation If not specified, the function assumes the default value of500
Trang 2After displaying the last individual image of the animation sequence, the function repeats the animation
in the opposite direction (that is, starting with the prior image and decrementing) After displaying thefirst image again, the animation repeats in the forward direction
If not specified, the function assumes the default value of back
</script>
The HTML tag to end JavaScript code
19.6.3.3 Inserting a Data Table
The following example JavaScript code creates a data table in the HTML report that you are assembling Ifthe specified table is not available, your report will contain a message indicating the problem
<script LANGUAGE="JavaScript1.2" SRC="ansysTables.js"> </script>
<script>
tableName('tableCaption');
</script>
Following is an explanation of the JavaScript code:
<script LANGUAGE="JavaScript1.2" SRC="ansysTables.js"> </script>
Loads the ansysTables.js file to provide the data table You must include this line of code at least
once in your HTML document and before calling the tableName function Typically, this line appears
in the <HEAD> section of an HTML document
Following is an explanation of the JavaScript code:
<script LANGUAGE="JavaScript1.2" SRC="ansysListings.js"> </script>
Loads the ansysListings.js file to provide the listing You must include this line of code at least
once in your HTML document and before calling the listingName function Typically, this line appears
in the <HEAD> section of an HTML document
<script>
The HTML tag to begin JavaScript code
Trang 3The HTML tag to end JavaScript code
19.7 Setting Report Generator Defaults
This section describes how to change settings affecting report generator operation Click on the Settings button to open the Settings dialog, as shown:
Figure 19.4: Report Generator Settings Dialog
You can control whether or not the report generator:
• Reverses the foreground and background colors in the ANSYS Graphics window (and hides the
back-ground image) when you start the report generator
• Writes capture commands to the ANSYS log file
• Writes your assembled report to the ANSYS log file
You can also use the Settings dialog to set the percentage value that the report generator uses to reduce
image sizes for animations
By default, all options are activated (that is, all check boxes contain check marks) and the report generator
uses an image size of 100 percent of the ANSYS Graphics window size for animations Any changes that
you make in the settings window become the new defaults for subsequent report generator sessions untilyou change them again
19.7 Setting Report Generator Defaults
Trang 5Chapter 20: File Management and Files
The ANSYS program uses many permanent and temporary files during an analysis The following agement topics are available to help you understand how ANSYS handles files and what you can do tocustomize and manage files:
file-man-20.1 File Management Overview
20.2 Changing the Default File Name
20.3 Sending Output to Screens, Files, or Both
20.4.Text Versus Binary Files
20.5 Reading Your Own Files into the ANSYS Program
20.6 Writing Your Own ANSYS Files from the ANSYS Program
20.7 Assigning Different File Names
20.8 Reviewing Contents of Binary Files (AUX2)
20.9 Operating on Results Files (AUX3)
20.10 Other File Management Commands
20.1 File Management Overview
The ANSYS program uses files extensively for data storage and retrieval, especially when solving an analysis.The files are named filename.ext, where filename defaults to the jobname, and ext is a unique two-
to four-character value that identifies the contents of the file The jobname is a name you can specify whenentering the ANSYS program via the /FILNAME command (Utility Menu> File> Change Jobname) If youspecify no jobname, it defaults to FILE (or file)
File names (both jobname and extension) may appear in lowercase on some systems For example, if thejobname is bolt, you may have files at the end of an ANSYS analysis which could include:
Database filebolt.db
Element matricesbolt.emat
Error and warning messagesbolt.err
Command input historybolt.log
Results filebolt.rst
Table 20.1: Temporary Files Written by the ANSYS Program (p 307) and Table 20.2: Permanent Files Written by the
ANSYS Program (p 308) show a list of files written by the ANSYS program Files that are generated and then deleted sometime before the end of the ANSYS session are called temporary files (Table 20.1: Temporary Files Written by the ANSYS Program (p 307)) Files that remain after the ANSYS session are called permanent files
(Table 20.2: Permanent Files Written by the ANSYS Program (p 308))
20.1.1 Executing the Run Interactive Now or DISPLAY Programs from Windows Explorer
If you are running ANSYS on a Windows system, you can double-click on the following types of files fromthe Windows Explorer to execute the Run Interactive Now or DISPLAY programs:
Trang 6• Double-click on a db or dbb file to execute the Run Interactive Now program When executed in
this way, ANSYS will use the Initial jobname, Total Workspace (-m), and Database (-db) values
previ-ously set in the Interactive dialog box To change these settings, access the Interactive dialog box (selectInteractive from the ANSYS folder), change the settings as desired, and click on Close
• Double-click on a grph or f33 file to execute the DISPLAY program The first plot that appears inthe file will be loaded into DISPLAY automatically
For more information about the Interactive dialog box, see the Operations Guide For more information aboutthe DISPLAY program, see Using the DISPLAY Program to View and Translate Neutral Graphics Files (p 285) inthe Basic Analysis Guide
20.2 Changing the Default File Name
When you activate the ANSYS program, you can change the default jobname from file or FILE to a namethat is more meaningful To do so, activate the program as follows:
ansys120 -j newjobname
The value -j (or -J) is an option indicating that a new jobname,newjobname, follows Once this commandexecutes, all ANSYS files produced during this run will have a filename of newjobname.ext
Note
If an ANSYS job is running in the background, do not execute the ANSYS program interactively in
the same directory unless you use a different jobname
ANSYS can process blanks in file and directory names Be sure the file name is enclosed in a pair of singlequotes if a blank appears in the file name Note that many UNIX commands do not support object nameswith blank spaces
20.3 Sending Output to Screens, Files, or Both
One of the files commonly referred to throughout the ANSYS documentation set is the output file (name.OUT) If you are running on a UNIX system and you want to send ANSYS output only to the screen,open the launcher via the launcher120 command Then select the Preferences tab and select Screen Only for the Send Output To option The output "file" will be your ANSYS output window If you choose Screen and File, then an actual text file called Jobname.OUT will also be written in your current workingdirectory
Job-Note
When you launch ANSYS from the launcher and direct output to both screen and file, ANSYS willnot immediately display output in the output window The I/O buffer must be filled or flushed
first Errors and warnings will flush the I/O buffer You can also issue certain commands (e.g.,
/OUTPUT, NLIST, or KLIST) to force flush the I/O buffer.
Windows systems do not support the Screen and File option The default behavior is to print output to the
output window You can redirect your text output to a file by using the /OUTPUT command
Trang 720.4 Text Versus Binary Files
Depending on how files are used, the program writes them in text (ASCII) form or binary form For example,ERR and LOG files are text, while DB,EMAT, and RST files are binary In general, files that you may need toread (and edit) are written in text form, and all other files are written in binary form
All binary files are external type files External binary files are transportable between different computer
systems
Below are some tips for using binary files:
• When transferring files via FTP (File Transfer Protocol), you must set the BINARY option before doingthe transfer
• Most ANSYS binary files must have write permission to be used, even if the data is only being read from
the file However, the database files (file.DB) and results files (file.RST,file.RTH, etc.) can beread-only When you save a read-only file.DB, the existing read-only file is saved to a file.DBB.However, you cannot save the read-only file.DB a second time, because it will attempt to write overthe file.DBB, which ANSYS will not allow
Warning
Binary files are not backward-compatible with previous releases of the ANSYS program For
ex-ample, you cannot use binary files produced by ANSYS 12.0 with release ANSYS 5.7 or earlier
Attempting to use binary files from later releases with an earlier release can cause serious
oper-ating problems in ANSYS For a list of the files that are upwardly compatible, see Table 20.2:
Per-manent Files Written by the ANSYS Program (p 308).
20.4.1 ANSYS Binary Files over NFS
You can access ANSYS binary files (for example,file.LN22,file.DB,file.RST) from NFS-mounteddisk partitions However, this usage is discouraged because heavy network traffic may result Also, networktraffic may cause NFS errors, which in turn can cause the ANSYS program to read or write an ANSYS binaryfile incorrectly
20.4.2 Files that ANSYS Writes
The following tables list the files that ANSYS writes
Table 20.1 Temporary Files Written by the ANSYS Program
Contents Type
Trang 8Contents Type
Identifi-er
Prevents more than one ANSYS job with the same name from running
in the same directoryBinary
Many of the permanent ANSYS files are upwardly compatible Files that generally can be used by future
re-leases of ANSYS have a Y in the Upward column.
Table 20.2 Permanent Files Written by the ANSYS Program
Contents Upward
Type Identifi-
er
ANSYS Neutral Format file, written by default by ANSYS after
a connection import [1]
Text
-ANF
Stores performance information when running the sparsesolver
Text
-BCS
Database for best design (optimization) [OPKEEP]
Binary
-BDB
Interpolated body forces written as BF commands [BFINT]
Text
-BFIN
FLOTRAN results file for best design (optimization) [OPKEEP]
Binary
-BRFL
Magnetic results file for best design (optimization) [OPKEEP]
Binary
-BRMG
Structural results file for best design (optimization) [OPKEEP]
Binary
-BRST
Thermal results file for best design (optimization) [OPKEEP]
Binary
-BRTH
Interpolated DOF data written as D Commands [CBDOF]
Text
Trang 9Contents Upward
Type Identifi-
Trang 10Contents Upward
Type Identifi-
er
Stores pivot information when running the default sparsesolver
Text
-RDF
Reduced displacements-
Element saved records, solution commands, and status for
a single substep of a load step (used for multiframe restart
of static and full transient analyses)
Many file compression utilities exist for UNIX (e.g., compress, gzip) and Windows (e.g., PKzip, WinZip) ANSYS
cannot read compressed files However, you can compress ANSYS models to save space when archiving, solong as you uncompress the models before trying to read them into ANSYS
Trang 1120.5 Reading Your Own Files into the ANSYS Program
In many situations, you will need to read in your own files while using the ANSYS program The file may be
a text file of ANSYS commands or a binary file of ANSYS data
Use the /INPUT command (Utility Menu> File> Read Input from) to read in a text file containing ANSYScommands For instance, you can read in the log file (Jobname.LOG) from a previous ANSYS session Forexample, the following command causes the ANSYS program to read the file MATERIAL.INP from thecurrent directory
Job-Main Menu> Preprocessor> Modeling> Create>
Ele-ments> Read Elem File
EREAD
Reads in node (name.NODE) files
Job-Main Menu> Preprocessor> Modeling> Create>
Nodes> Read Node File
NREAD
Reads in material property(Jobname.MP) files
MPREAD Main Menu> Preprocessor> Loads> Load Step Opts>
Other> Change Mat Props> Read from File
Main Menu> Preprocessor> Material Props> Read
from File
Main Menu> Solution> Load Step Opts> Other>
Change Mat Props> Read from File
Reads in initial state (name.IST) files
Job-This command cannot be accessed from a menu
Com-mand
Reads in database (name.DB) files
Job-Utility Menu> File> Resume from
Utility Menu> File> Resume Jobname.DB
Trang 12Job-Purpose GUI Menu Path
1 in the POST1 postprocessor
2 in the OPT postprocessor
20.6 Writing Your Own ANSYS Files from the ANSYS Program
Besides the files that the ANSYS program automatically writes during an analysis, you can also force files to
be written as necessary A commonly used file-write command is /OUTPUT, which allows you to redirecttext output from the screen to a file For example, to redirect POST1 stress printout to a file, the commandswould be:
/OUTPUT,STRESS,OUT! Output to file STRESS.OUT
PRNSOL,COMP! Component stresses
/OUTPUT! Output back to screen
GUI equivalents for the /OUTPUT command are:
GUI:
Utility Menu> File> Switch Output to> File
Utility Menu> File> Switch Output to> Output Window
Table 20.5: Other Commands for Writing Files (p 312) lists other file-write commands used during an analysisare:
Table 20.5 Other Commands for Writing Files
Purpose GUI Menu Path
Main Menu> Preprocessor> Modeling> Create>
Ele-ments> Write Elem File
EWRITE
Writes node definitions toJobname.NODE
Main Menu> Preprocessor> Modeling> Create>
Nodes> Write Node File
NWRITE
Writes material properties
to Jobname.MP
Main Menu> Preprocessor> Loads> Other>
Change Mat Props> Write to File
Main Menu> Preprocessor> Material Props> Write to File
MP-WRITE
Main Menu> Solution> Load Step Options> Other>
Change Mat Props> Write to File
You can also redirect graphics output (plots) from the screen to a neutral graphics file
Trang 1320.7 Assigning Different File Names
As mentioned earlier, you can use the /FILNAME command at the Begin level to assign a jobname for allsubsequently written files Use the /ASSIGN command (Utility Menu> File> ANSYS File Options) to assign
a different name, extension, and directory to a file For example, the following command reassigns the elementmatrix file (identifier EMAT) to MYFILE.DAT in the "save_dir" directory:
/ASSIGN,EMAT,MYFILE,DAT,SAVE_DIR/
The "/" is a delimiter that separates the directory name from the file name It is system-dependent, so youmust use the delimiter(s) appropriate for your system You can assign only a specific set of files Refer to the
/ASSIGN command description (in the Command Reference) for the complete list.
20.8 Reviewing Contents of Binary Files (AUX2)
The auxiliary processor AUX2 allows you to print ANSYS binary files in readable format Use it mainly to
verify file formats (for debugging purposes) The output from a "dumped" binary file is unlabeled and must
be correlated with known formats documented in the Guide to Interfacing with ANSYS Be aware, though,
that a complete file dump may produce many pages of unnecessary printout The Format argument onthe FORM command (Utility Menu> File> List> Binary Files) allows you to control the amount of output.Use the HBMAT command to dump any matrix written on the assembled global matrix file (.FULL file) orthe superelement matrix file (.SUB file) This matrix is written to a new file (.MATRIX) in the standard
Harwell-Boeing format
Note
The Harwell-Boeing format is column-oriented That is, non-zero matrix values are stored with
their corresponding row indices in a sequence of columns However, since the ANSYS matrix files
are stored by row and not column, when the HBMAT command is used with a non-symmetric
matrix, the transpose of the matrix is, in fact, written
Use the PSMAT command to write a postscript file containing a graphic representation of any matrix on
the FULL file The matrix is symbolized by a grid in which colored cells represent the nonzero coefficients
of the matrix See the PSMAT command for details
20.9 Operating on Results Files (AUX3)
The auxiliary processor AUX3 allows you to operate on results files by deleting sets or by changing valuessuch as the load step, load substep, cumulative iteration, or time
20.10 Other File Management Commands
Table 20.6: Additional File Management Commands and GUI Equivalents (p 313) lists other useful file managementcommands
Table 20.6 Additional File Management Commands and GUI Equivalents
Purpose GUI Path
Trang 14Purpose GUI Path
Com-mand
Copy the log file during aninteractive ANSYS sessionNone
Delete certain files during
a solution run (to save diskspace)
Utility Menu> File> ANSYS File Options
/FDELE
Trang 15Chapter 21: Memory Management and Configuration
The amount of physical memory (RAM) available on your computer is called real memory The minimum
amount of real memory recommended for the ANSYS program varies from system to system and is listed
in your ANSYS, Inc Installation Guide It is helpful to understand the ANSYS memory-management scheme
and some frequently used terms concerning computer memory
The following memory-management topics are available:
21.1 ANSYS Work and Swap Space Requirements
21.2 How ANSYS Uses its Work Space
21.3 How and When to Perform Memory Management
21.4 Using the Configuration File
21.5 Understanding ANSYS Memory Error Messages
To learn how to improve the performance of the ANSYS program, see "Using Shared-Memory ANSYS" in the
Advanced Analysis Techniques Guide.
21.1 ANSYS Work and Swap Space Requirements
The ANSYS program requires some space to reside in memory, plus additional work space The ANSYS workspace defaults to 1 GB (1024 MB) for 64-bit machines, and 512 MB for 32-bit machines (Linux and Windows)
As shown in Figure 21.1: Comparing Available Memory (p 315), the total memory required for the ANSYS program
usually exceeds the amount of real memory available The additional memory comes from system virtual
memory, which is simply a portion of the computer's hard disk used by the system to supplement physical
memory The disk space used for system virtual memory is called swap space, and the file is called the swap
file On some systems it is referred to as a page file Other systems maintain multiple files, or even dedicated
disk sectors to act as virtual memory The amount of swap space required for the ANSYS program depends
on the amount of real memory available, the size of the ANSYS executable, and the amount of ANSYS workspace
Figure 21.1: Comparing Available Memory
System virtual memory is used to satisfy additional ANSYS memory requirements
21.2 How ANSYS Uses its Work Space
To understand how ANSYS uses its work space (the shaded portion in Figure 21.1: Comparing Available
Memory (p 315)), you need to understand its two components: database space and scratch space, as shown
Trang 16in Figure 21.2: ANSYS Work Space (p 316) Database space is used to work with the ANSYS database (modelgeometry, material properties, loads, etc.) Scratch space is where all internal calculations are done - elementmatrix formulation, equation solution, Boolean calculations, and so on The default total work space for 64-bit machines is 1 GB (1024 MB), of which 512 MB are assigned to database space, and 512 MB are assigned
to scratch space For 32-bit machines, the default work space is 512 MB, of which 256 MB are assigned todatabase space, and 256 MB are assigned to scratch space (Part of the scratch space stores binary file buffers;see the description of NUM_BUFR later in this chapter.)
Figure 21.2: ANSYS Work Space
If your model database is too big to fit in the database space, the ANSYS program uses ANSYS virtual memory, which is, again, a portion of the hard disk used for data overflow The main difference between system virtual memory and ANSYS virtual memory is that the former uses system functions to swap data between memory
and disk, whereas the latter uses ANSYS programming instructions The file used for ANSYS virtual memory
is called the page file and has the name Jobname.PAGE Its size depends entirely on the size of the database.When the page file is first written, the program issues a message to that effect Use of the page file is notdesirable because it is a less efficient way of processing data You may be able to prevent it by allocatingmore database space (discussed in How and When to Perform Memory Management (p 316))
If internal calculations can't fit in the scratch space, the ANSYS program will attempt to allocate additionalmemory to meet these requirements If this occurs, you will see an alert message informing you that theproblem has grown beyond the specified memory allocation and that ANSYS has allocated additional memory
In general, you should have enough real physical memory to comfortably run an ANSYS job If you are usingextra memory beyond physical memory only temporarily (such as for meshing or equation reordering), theperformance impact from using virtual memory will be small However, in a situation such as the matrix
storage for the PCG solver exceeding physical memory, the performance can be as much as ten times slowerfor the solve command
21.3 How and When to Perform Memory Management
Normally, there is no need to concern yourself with memory-management issues in ANSYS The ANSYS
memory manager can allocate extra memory from the system when it needs to in almost all cases.
The following sections provide guidance as to when it is likely that you will need to use the -m commandline option
21.3.1 Allocating Memory to ANSYS Manually
21.3.2 Changing the Amount of ANSYS Work Space
Trang 1721.3.3 Changing Database Space From the Default
21.3.1 Allocating Memory to ANSYS Manually
The -m command line option allows you to manually set the size of the initial block of memory used byANSYS Memory allocated via the -m option exists in two contiguous blocks For example, a -m setting of
1800 with a -db option of 300 instructs ANSYS to first allocate a 300 MB contiguous block of memory forthe database and then to allocate a 1500 MB contiguous block of scratch memory (1800 - 300 = 1500).The current ANSYS default for all 64-bit systems is -m = 1024 and -db = 512 For 32-bit Windows and Linuxsystems, the defaults are -m = 512 and -db = 256 Ideally, all ANSYS memory will be allocated from withinthe initial block, allowing efficient reuse of memory blocks during various phases of simulation When ANSYSneeds more memory, it will allocate from the system, automatically growing new blocks that are half thesize of the initial scratch memory block or the size of the new memory block allocation, whichever is larger.Changing the default memory settings is only necessary when a job is failing due to insufficient memorythat may be caused by fragmented memory
For example, if a large model requires a contiguous block of 800 MB for the sparse solver, the default memoryallocation will be insufficient (-m 1024 MB minus -db 512 MB = 512 MB contiguous memory) ANSYS wouldtry to allocate an additional 800 MB block of contiguous memory to satisfy the sparse solver requirement,bringing the total memory requirement to 1800 MB (1024 default plus 800 additional) This memory require-ment may fail on smaller systems, especially 32-bit Windows systems To accomodate this model within thedefault memory availability, specify a -db 100, resulting in an initial memory block of 924 MB, which is suf-ficient to satisfy the sparse solver requirement of 800 MB If you are running a 32-bit Windows system, seeMemory Usage on Windows 32-bit Systems for more information about that system
21.3.2 Changing the Amount of ANSYS Work Space
The easiest way to do this is to use the work space entry option (-m) while activating the program, eithervia the ANSYS launcher or via the ANSYS execution command For example, to request 400 MB of ANSYSwork space (instead of the default of 1 GB for 64-bit machines or 512 MB for 32-bit machines), the ANSYSexecution command would read:
ansys120 -m 400
(The execution command syntax is system-dependent.)
When you use the -m option, system virtual memory is allocated at run time to achieve the work space quested
re-Other ways to change the maximum ANSYS work space are:
• Specifying the work space size you want on the dialog boxes that appear when you select interactivemode or batch mode from the ANSYS launcher
• Using a different VIRTM_MB value in your config120.ans file A later section in this chapter discussesthis file in detail
Caution
Be careful when specifying a value for the -m option Entering an amount larger than needed
will waste system resources and degrade system performance
21.3.2 Changing the Amount of ANSYS Work Space
Trang 18By changing the amount of ANSYS work space, you are in effect changing the available scratch space This
is because the database space is held constant at 512 MB for 64-bit machines or 256 MB for 32-bit machines(as illustrated in the following figure)
Figure 21.3: Changing ANSYS Work Space
Only scratch space is changed, and database space is held constant
The following list describes situations in which you may need to change ANSYS work space:
• Boolean operations among several volumes (for example,VADD,ALL) You need more scratch space in
such a case This is an example where a large memory space may be needed temporarily and may besatisfied from system virtual memory
• Several users sharing one ANSYS installation (such as in a training class) Because all users share theavailable memory (real memory plus system virtual memory), having less ANSYS work space requested
by each user would allow more users to run simultaneously (with correspondingly smaller model sizesavailable for each user)
• Some analyses and analysis options require more work space, including random vibration (PSD) analysis,etc In the case that such an analysis is right at the limit of physical memory, you should conserve
memory by reducing database memory In cases where you are running up to the physical limits of themachine, increase the initial memory block given to ANSYS in order to maximize the possibility of
memory reuse within the ANSYS runs
• Large number of element or nodes The larger the number of active elements or nodes in your model,the more scratch space needed
Most solvers in ANSYS now use approximately 1 GB of memory per million degrees of freedom (DOFs) Ifmodels are dominated by 2-D or shell elements, the memory requirement will be lower; if they are dominated
by 3-D higher-order brick elements, the memory requirement will be higher The sparse solver will run largerjobs in out-of-core mode and will require disk space of approximately 10 GB per million DOFs The disk
memory requirement varies in the same increasing manner for shell 2-D models versus solid 3-D models Ifthe solver memory estimate far exceeds the default memory for ANSYS, try increasing the initial memoryallocation for ANSYS
21.3.3 Changing Database Space From the Default
This is done by requesting more or less database space Given a fixed amount of ANSYS work space, allocatingmore database space leaves less for scratch space and vice versa, as illustrated in the following figure