The following characteristics apply to commands:
The data input for each command is described in this manual. Data should not be input in any undocumented field, nor should other than documented values be input in any field. Also, the data input described in this manual should not be used with any earlier version of the program. Some features that allow easy input of data are free-format, nonrestrictive, and condensed input.
Free-format capability allows the user to input data in consecutive fields without having to space to each field. The comma (,) character effectively ends the field so that the next character will be input in the beginning of the next field. A blank field is skipped by having no data item between the commas. Fields are assumed to be as wide as the number of characters specified. Input is converted to formatted fields when coded files are written (of width large enough (16 characters maximum) to minimize loss of accuracy).
Significant figures of output should not be expected to match that of input. Machine precision, rounding of numbers when writing internal scratch files, etc., tend to lower the precision during the analysis.
Nonrestrictive data input allows the user to enter any form of data in a field and the ANSYS program will interpret it as required (integer, real, or alphabetic) or ignore it. Double precision is used throughout the program for all real numbers. Alphabetic data may be entered in upper or lower case. Lower case is internally converted to upper case within the program (except for case-sensitive applications, such as in comments, (text preceded by a !) titles, and file names.)
The following features are available with the nonrestrictive data input.
No distinction is necessary between real and integer data.
Data may be placed anywhere within the field.
Real data input without a decimal point has the decimal point assumed after the right-most digit.
Real number values input to integer data fields will be rounded to the nearest integer. The absolute value of integer data must fall between zero and 2,000,000,000.
Element and node numbers (IDs) should be between 1 and 999,999,999. Element type, material reference, real constant, section, and coordinate system IDs should be between 1 and 9,999,999. IDs larger than these may not be written out correctly in listings (xLIST commands), CDWRITE files, LSWRITE files, and other text-based output files.
Exponents may be input in the field after the number. The E (or D) character must be used (upper or lower case). The sign after the E character is assumed to be the sign associated with the exponent (the absence of a sign is assumed to be +). The acceptable range of values for real data is +/-1.0E+200 to +/-1.0E-200.
A nonnumeric character in the numeric field (other than a valid convenience label, a parameter name, or an E or D exponent character) will be ignored and will cause the remainder of the field to be ignored. When the program can accept an alphanumeric label in a field, it will interpret any alphanumeric input that matches a valid label as the appropriate label. In other words, the program will not interpret a valid label as an identically named parameter. If you truly want to use a parameter in place of a valid label, you can use forced parametric substitution (using % signs). A non-alphanumeric character in a label field is taken as part of the label. Non-alphanumeric characters (such as CONTROL-characters, TAB-characters, and other terminal editing characters) should be avoided since they may be used directly instead of being interpreted by the terminal.
An option for condensing the data input is available with the $ character. This character effectively ends a command and allows the next command to begin on the same line (at the next column). The line must not extend beyond 640 characters (including all commas and $ signs). If a command cannot be completed on the line, it should begin on the next line. Blank commands are ignored. The $ character should not be used following any command that causes a file switch to read additional commands (such as the /INPUT, *USE, CDREAD, etc. commands, any "unknown command" macro, or any do-loops or if-then-else constructs). The $ character should not be used between a command and its required following format line (such as *VREAD, *VWRITE, *MSG, etc.). The $ character should not be used after the ALLSEL command. Using the $ character in interactive mode may result in unexpected output behavior.
The ANSYS program permits the use of any consistent set of units for length, force, time, temperature, etc. Care must be taken to ensure that all input data are in the same set of units. The /UNITS command may be used to note the system of units being used. Temperatures may be absolute or relative in most cases. For problems requiring absolute temperatures, such as those involving creep, swelling, or radiation, temperatures may be input as Celsius or Fahrenheit, for convenience, with a temperature shift from absolute zero [TOFFST].
To minimize the amount of data input, most commands have defaults which apply both to the command itself and to any arguments.
Command Defaults
A command default refers to the specification or behavior that is assumed when a command is not issued. For example, if you do not issue the /FILNAME command, the jobname defaults to FILE (or whatever jobname was specified when you entered the program).
Argument Defaults
An argument default is the value assumed for a command argument if the argument is not specified. For example, if you issue the command N,10 (defining node 10 with the X, Y, Z coordinate arguments left blank), the node is defined at the origin; that is, X, Y, and Z default to zero.
Values for numeric arguments (such as X, Y, Z) typically default to zero, although exceptions exist for some commands, such as those with arguments specifying coefficients or tolerances. Such exceptions are noted in the documentation for those commands.
When an argument has a nonzero default, entering a blank or a zero for that argument triggers the nonzero default value. If an effective zero is desired for such an argument, input a very small number (such as 1E-14) instead.
In cases where no default is indicated or obvious for an argument, enter the desired value. Such arguments have no favored default value and require an explicit input value.
Some Command Defaults May Differ According to Product The defaults for some commands and their arguments may differ depending on which product is using the commands. The "Product Restrictions" section of the descriptions of the affected commands clearly documents such cases. If you intend to use your input file in more than one product, it is good practice to explicitly specify commands and argument values, rather than letting them default. Otherwise, behavior in the other product may differ from what you expect. |
Various files are used during a session for reading, writing, and storing data. Program-generated files are identified by a name, a system-dependent separator, and an extension (as in the form fname.ext).
The name is obtained from the Jobname (250 characters maximum, including the directory name) as defined with the execution command. (Windows cannot create directory names longer than 245 characters.)
Unless otherwise specified, the Jobname defaults to a system-dependent name (usually FILE). The extension is a two- to four-character identifier. (See Files that ANSYS Writes in the Basic Analysis Guide.) For example, the error message file (which has
the identifier ERR) with a jobname of FILE and separator (.) would be generated as FILE.ERR. If the Jobname is JOB1, the file would be named JOB1.ERR. The documentation
generically refers to program-generated files as Jobname.identifier, such as Jobname.ERR for the error message file. Unless otherwise indicated, files are
written in the current working directory.
Some commands (such as /INPUT and /OUTPUT) allow you to specify a file name other than Jobname, and an extension other than the default extension. Such user-written files use a naming convention similar to the ANSYS-generated files except that the name (248 characters maximum, including the directory name) is user defined, and the extension (8 characters maximum) is optional. The file name can include the directory path, but it is not necessary if you want to use the default directory. File names containing directory paths must reference existing directories. File and directory names may contain blank spaces, but strings containing blank spaces must be enclosed in single quotes.
A system dependent separator is automatically written between file name and extension (if the extension exists) input on commands.
File name fields are usually restricted to 248 characters (including the directory name) in command inputs. If you specify no directory path, the default path is your working directory, and you can use all 248 characters for the file name.
To help ensure portability of input files across systems, the program has certain requirements for file names. File names specified by the user should contain ASCII alpha-numeric characters. Avoid using special characters (+,-,*,/,$,!, etc.) in file names unless meaningful, and begin file names with a letter. Some system-dependent special characters (such as ~) are not interpreted the same as they are at the operating system level when used in path names. Parameter substitution may be forced within the name, extension, or directory fields by enclosing the parameter within percent (%) signs. For example, if I = 5, the name TEST%I% becomes TEST5. Only one forced substitution may be made per field.
The slash (/) and star ( *) commands are usually used for supplying general control instructions to the program. For example, slash commands are used for entering a processor (/PREP7, /POST1, etc.). Printout controls, display controls, and file controls are available within the slash command set.
Repeat, looping and macro controls are available within the star command set.
Many star and slash commands are global and apply to all processors. For example, the /TITLE command may be used to change the title in any processor (PREP7, POST1, etc.). The star commands can be input anywhere. Most slash commands can be input anywhere; however, some can only be input at a Begin level, and those commands are specifically noted in the command description. Graphics displays are controlled via the graphics display slash commands. The graphics display slash commands can be input anywhere.