2.14. Postprocessing Nonlinear Mesh Adaptivity Results

For nonlinear mesh adaptivity, the POST1 postprocessor (/POST1) is the primary postprocessing tool and most of its capability is available. Animation is also available via the ANDATA macro.

Each time the adaptivity criteria are satisfied, the mesh changes, so new .rdb files are necessary. For example, if you have two mesh changes during the same analysis, the program writes the following database files: .rdb, .rd01, and .rd02. (For more information, see File Structures for Repeated Rezonings.)

Most POST1 postprocessing operations proceed seamlessly from one database file to the next automatically; therefore, do not delete the .rst or .rdb file, nor any .rdnn files, until you have completed postprocessing.

The displacements listed or plotted are not the total displacements from the beginning of the loading, but the displacements from the last splitting or remeshing.

When listing solution results (SET,LIST), each substep that starts with a new mesh is marked: mesh changed

2.14.1. Using the Database Postprocessor (POST1)

Keep all .rdb and .rdnn database files until all desired postprocessing work has been completed. The POST1 postprocessor is dependent on the .rst results file, and on the .rdb and .rdnn files. If all or some of the database files are lost, the program uses the .rst file to recover as much data as possible. In such cases, however, data that exists only in database files may no longer be available, causing some postprocessing operations to behave unexpectedly. For example, information about defined components (CM), body-force loads on nodes (BFLIST), and surface loads (SFLIST) may be missing.

If you exited the program after the solution phase of the analysis and now want to perform POST1 postprocessing on your rezoning results, issue /FILNAME to specify the appropriate jobname before entering the POST1 processor. This is the preferred method for postprocessing rezoning results.

2.14.1.1. Listing the Nonlinear Mesh Adaptivity Results File Summary

After entering the POST1 processor, it is helpful to issue SET,LIST.

For nonlinear mesh adaptivity, the output list generated by the command indicates when a mesh change (and corresponding database file change) occurs, as shown in this example:

*****  INDEX OF DATA SETS ON RESULTS FILE  *****

   SET   TIME/FREQ   LOAD STEP   SUBSTEP  CUMULATIVE
    1    0.10000         1          1         4                  
    2    0.20000         1          2         9   mesh changed
    3    0.30000         1          3        14   mesh changed
    4    0.40000         1          4        18   mesh changed
    5    0.50000         1          5        19                
    6    0.60000         1          6        20                  
    7    0.70000         1          7        24   mesh changed
    8    0.80000         1          8        26                
    9    0.90000         1          9        28                  
   10    1.0000          1         10        31   mesh changed

2.14.1.2. Animating the Nonlinear Mesh Adaptivity Results

Animation for nonlinear mesh adaptivity is available via the ANDATA macro.

Assuming that the appropriate jobname is already specified, the program proceeds from one mesh to the next automatically, using the data in each to generate the animation.

During the macro's initial scan, the program stores the view location and size of every saved substep. The program then combines the data to provide one fixed view (by internally setting the /FOCUS and /DIST commands to fixed values).

2.14.2. Using the Time-History Postprocessor (POST26)

When using the POST26 time-history postprocessor (/POST26) on a model that has undergone remeshing, all of the usual information is available. Access it as follows:

  1. Reset (RESET) the postprocessor specifications to initial defaults, erase all defined variables, and clear the data storage space.

  2. Resume (RESUME) the appropriate .rdnn database file (generally the one corresponding to the most recently created mesh).

  3. Open (FILE) the .rst results file.

Only the output information available is fetched from the results file, as elements and nodes that exist in one mesh do not always exist in another.