The NASTRAN Door reads and checks model files compatible to NASTRAN and translates these input files directly into internal PERMAS data structures.
The main capabilities of the NASTRAN-Door are:
- All Bulk Data formats are supported: Small Field, Large Field and Free Field (with all possibilities for card generation).
- Executive and Case Control sections are translated as well as all global usable statements.
- PERMAS Components and Situations are built according to the Bulk Data model and the selections made by physical Case Control requests.
- Take-over of NASTRAN identifiers, e.g. element-, node- and set-IDs survive the interfacing process and will be taken as PERMAS identifiers.
- Automatic label generation with labels compatible to those generated by NASTRAN.
- Fast Bulk Data sorting with machine independent sort sequence.
- NASTRAN-like echo of input statements.
- Extensive error tests are performed:
- All public NASTRAN statements are recognized and analyzed lexically.
- All supported statements are completely checked for wrong, missing or contradictory arguments.
- Additional features:
- Calculated results may be referenced under Subcase- or Load-ID.
- Free Field comments within Fix Field statements.
- the INCLUDE statement supports multiple file levels.
A remarkable specialty of the NASTRAN-Door is the ability to utilize the given control data as well:
Control input such as solution-ID, output requests and method selections are converted into task control structures, equivalent to those made by explicit UCI input (User Control Interface).
This so-called NASTRAN Task may be started by one special UCI statement.
To execute a NASTRAN-compatible run, only 4 PERMAS UCI-commands are necessary (see figure). Using this simple UCI input, NASTRAN decks can be executed without the necessity of any additional input.
Additional features of this NASTRAN Task are:
- Automatic re-translation of its internal task definitions into plain UCI commands echoed to the user.
- The user can choose between the automatic solution control (read from the given NASTRAN model file) and an explicit UCI control.
- The user can extend the NASTRAN Task by additional UCI statements.
- NASTRAN subcases may be selected and executed individually, leaving all remaining subcases untouched.
- the following solutions are supported:
- Linear Static,
- Normal Modes Analysis,
- Direct Frequency Response,
- Direct Transient Response,
- Modal Frequency Response and
- Modal Transient Response.
- Supported parameters, which affect the control flow, are also evaluated.
Finally the application of the NASTRAN Task is not restricted to pure NASTRAN-Door input. Even if model additions were made by other input Doors (e.g. DAT file input) - the user is free to execute his/her NASTRAN control data, automatically.