3 EDITING INPUT FILES

3.1 GENERAL INFORMATION

Z88 works with the following files:

(1) Input Files:

Z88I1.TXT (general structure data, coordinates, coincidence, material informations)
Z88I2.TXT (boundary conditions, loads, constraints)
Z88I3.TXT parameters for stress processor Z88D)
Z88I4.TXT (parameters for the sparse matrix solvers Z88I1/Z88I2 and Z88I1/Z88PAR)
Z88I5.TXT (surface and pressure loads – if needed)
Z88NI.TXT (input file for the mesh generator)

Produce these input files with your CAD program and the CAD converter Z88X or with a 3D CAD system creating COSMOS files and converting them with Z88G or with an editor (e.g. Notepad of Windows, Emacs, Joe at UNIX) or word processing program (e.g. Word for Windows at Windows). If using a word processor systems keep in mind to edit pure ASCII texts without any hidden control characters ... every word processing program has such an option. Why not using your own editor (if you do not want or cannot work with a CAD program) ?

So how you can work with the editor/word processor you are familiar with and used to.

Details to the input files see sections 3.2 pp.

(2) Output Files:

Z88O0.TXT (processed input data for documentation)
Z88O1.TXT (processed boundary conditions for documentation)
Z88O2.TXT (calculated displacements)
Z88O3.TXT (calculated stresses)
Z88O4.TXT (calculated nodal forces)

The files Z88O5.TXT and Z88O8.TXT are not regular Z88 output files, containing the coordinates of the stress points and the reduced stresses for use for the plot program Z88O internally. It is a pure ASCII file, so that advanced users can use it for own routines, if necessary.

(3) Binary Files:

These files are used internally and are not for editing. They serve the fast data interchange between Z88 modules.

Z88O1.BNY
Z88O3.BNY
Z88O4.BNY (only for internal communication of the sparse matrix solvers)

Why work with files? Is that not old-fashioned and does "interactive" working not do a better job? Z88 is designed as an open, transparent system according to the UNIX philosophy: Several, compact modules communicate via files together.

- A maximum of memory is useable for the FE data, because always only relatively small, compact programs are loaded into memory.
- Z88 is very flexible and adaptable through its open structure. Any kind of preprocessing and postprocessing is possible without restrictions. You can generate the input files by small, self-written preprograms (such a preprogram is the mesh generator Z88N ) or leave the job of processing the output data to other programs: You can quite easily load Z88 output files into EXCEL and analyse there.
- Every FEA program can, and so does Z88, produce a huge amount of data junk from time to time. You are very often interested only in very specific results, e.g. of special nodes. The output files are simple ASCII files. You can edit and shorten them as you like and print only the really interesting results.
- Very often input files are produced much faster than by any interactive queries: Many input lines are similar to prior lines: Use the block operations of your editor for copying !

Downward compatibility:

Z88 files for V11.0 and V12.0 are okay for Z88 V13.0, if the the plate flag and the surface and pressure loads flag are supplied.

Rules for entering values:

There is no need for special rules or field divisions, only the usual C rules apply:

- All values are to be separated by at least one blank
- Integer numbers may contain any point or exponents
- For floating point numbers no points need to be provided
- Numerical values which are 0 (zero), have to be entered explicitly.

Integer numbers

Correct | 1 | 345 | 55555 | 0
Wrong | 1. | 345. | 55555E+0 | no entry

Floating point numbers (Z88 uses internally double precision floating point numbers [Double])

Correct | 1. | 345 | 5.5555E+10 | 0
Wrong | 1, | 345, | O (letter O) | no entry

Z88 input files may have comments in every line if all corresponding data has been filled out before. Separate the last data and the comment at least by one blank. Lines in Z88 input files can include 250 bytes (really needed are noticeably less than 80). Blank lines and pure comment lines are not permitted.

Always check input files with Z88V before a Z88 run.

- Z88V checks for formal correctness of the entry files. It can hardly recognize wrong or useless structures and boundary conditions. Examine when error messages or abnormal program stops of Z88:
- Are the files really pure text files, well in the ASCII format? Or have there been added unnoticed hidden control characters by your text processor ?
- Is the last line of an input file terminated by at least one RETURN ?

- Is MAXKOI in Z88.DYN large enough? If in doubt enter 1000000 or higher for MAXKOI.
- Is your structure statically determined or in any way statically overdefined (allowed !)? Or is it statically indetermined, i. e. boundary conditions are missing which may cause serious trouble. Statically indetermined structures can appear easily for Beams No.2 , Cams No.5 and Beams No.13 (take care of the rotation degrees of freedom).
- Is the coincidence list defined properly? Especially Hexahedrons No.10 are very sensitive to wrong numbering.
- Plot the initial structure with Z88O . If you will not see some pretty good stuff, then the rest can hardly become better!
- Always do a rough calculation! Are the calculated deflections extremely high? Then check the boundary conditions quite carefully!
- And for the UNIX operating system: Are the file permissions properly set? For the .LOG files too ? Do a chmod 777 !
- Z88 input files for UNIX and Windows have the same structure. You can without restriction load Z88-UNIX files into Windows and vice versa. But did you do the proper conversion? Windows terminates lines by a CR/LF, but UNIX only by a LF ! Many LINUX systems feature the converters unix2dos and dos2unix.