I/O Options and Subcase Information Entry Used to define the prefix to be used for external eigenvalue data files (.eigv).


EIGVNAME = prefix


Argument Description
prefix The prefix to be used for the saving and retrieval of external eigenvalue data files.

The external eigenvalue data file name is of the form <prefix>_#.eigv, where <prefix> is defined here, # is the integer argument of the EIGVSAVE Subcase Information Entry or one of the integer arguments of the EIGVRETRIEVE Subcase Information Entry.


  1. When an EIGVNAME command is not present, the OUTFILE prefix definition is used. If OUTFILE is not defined, the prefix of the input file is used.
  2. Only one occurrence of EIGVNAME is permitted.
  3. EIGVNAME must appear before the first subcase.
  4. The total length of information on this card is limited to 200 characters (including the card name and spaces between arguments). This data can be on a single line or span multiple continuation lines. See I/O Options and Subcase Information Entries Guidelines for an example showing how to enter long file names on multiple lines.
  5. Prefixes specified on the EIGVNAME card can be arbitrary file prefixes with optional paths appropriate to the operating system (Windows or Unix). They may be enclosed in quotes (double or single quotes can be used), with either forward slash (/) or back slash (\) characters to separate parts of the path name.

    OptiStruct uses the following rules for the EIGVNAME card:

    • When the argument contains an absolute path of the file (if it starts with "/" on Unix or a drive letter, such as "D:", on Windows, for example), OptiStruct creates .eigv files at the given location.
    • When only the file prefix is given (without the path), .eigv files will be created in the current directory, meaning the directory from which OptiStruct has been executed, and NOT in the directory where the input file is located.
    • When the argument contains a relative path (../filename or sub/filename, for example), .eigv files will be created in a directory relative to where OptiStruct is executed and NOT relative to the directory where the input file is located.