Extraction of Nastran XDB file results into excel

Purpose of the excel workbook

The excel workbook discussed here allows to extract results from a Nastran XDB file in excel. The example, contains several worksheets with controls that are linked to excel VBA functions. These functions use the FeResPost COM component that performs the interactions with Nastran model and results. The VBA code is not described here. Those who are interested are referred to the FeResPost Reference Manual for more explanation.

The workbook we present here is provided with FeResPost COM example in "COMEX/EX09/PostXdbRandom.xls" excel file. To run this example, you need to register properly the corresponding version of FeResPost COM component. (The way to do it is explained in FeResPost Reference Manual.)

Note that a similar "COMEX/EX09/PostDesFacRandom.xls" worksheet allows ,to perform similar operations with SAMCEF models, and results extracted from DES & FAC files.

"FemDbIds" worksheet

The first worksheet in which on has to work is the "FemDbIds" worksheet that is used to read the finite element model, and attach an XDB file. Several control buttons allow to perform this operation:

In cells C3, C4 and C5, one specifies the Nastran main BDF file, the Patran group session file, and the Nastran XDB file. The full path must be specified, and this can be done manually by filling the cells. Buttons "Select Bdf File", "Select Ses File" and "Select Xdb File" can also be used to fill the three cells.
Button "ReadModel" creates a database ("NastranDb" object), reads the model from BDF file, and the groups from Patran session file. The button also fills the content of columns "Groups" and "CoordSys" in the worksheet. (These columns are used as list references for Combo boxes in several extraction worksheets.)
Button "ScanXdb" attaches the XDB file to the database, and reads the corresponding load cases, sub-cases, and results identified in the XDB file. The content of columns "LC names", "SC names" and RES names are also filled.

Two other buttons allow to show or hide FeResPost window, and one button allows to close FeResPost. (This last button also destroys all the objects that have been created.)

Finally, an "Export Groups" button allows to save the database groups in a Patran session file.

"ResExtract" worksheet

The "ResExtract" worksheet allows the extraction of Results from the XDB file attached to the current database. Several controls allow to perform this operation:

A combo box allows to select the group of elements and/or nodes on which the values are extracted. This first combo box is completed by two combo boxes:

The first one defines on which types of entities the results are extracted: "Elements", "Nodes", "ElemCenters", "ElemCorners", "ElemNodes"...
The second one allows to specify the layers on which results are extracted. It can be all the layers, or a selection of layers input in the spreadsheet. (In the example provided, the selection corresponds to cells in range M2Q11.)

A Combo box allows to select the load case for which results are extracted.
A Combo box allows to select the sub-case for which results are extracted. Note that in some cases you have to be careful to choose a sub-case corresponding to the load case you have selected. This difficulty can occur when you are extracting results for Nastran SOL 105, SOL 106, SOL 108, SOL 111...
A Combo box allows you to select the result you are extracting. (In the example below, one extracts the complex Beam forces in real-imaginary format.)
One Combo box, and one check box allow to define the coordinate system in which the components of the extracted result are expressed. If one checks the "Projected CS" box, the vector define in cells D12:F12" specifies the projected vector.

Finally, the "Extract" button allows to extract the results and fills the spreadsheet starting at line 15. Note that the results are sorted by increasing element ID, node ID, layer ID and sub-layer ID.

"ResExtractCombili" worksheet

"ResExtractCombili" is a variant of "ResExtract" worksheet that allows the extraction of linear combinations of elementary load cases results. It differs from "ResExtract" by:

The fact that three load cases must be specified.
The fact that three factors must be associated to the three sub-cases. Three Scroll bars allow the modification of these factors, but the factors can also be input manually.

This worksheet can be useful when the sizing is done using combinations elementary load case results as acceleration load cases.

"WorstResExtract" worksheet

This spreadsheet allows to extracted a limited number of results (the worst one according to a specified criterion). More precisely:

A Combo box allows to specify according to which criterion the worst results are selected. Note that in this case, the largest values are extracted.
A Scroll bar allows to specify the number of values one wishes to extract. This value can also be input manually.

Results are output by decreasing order for the selected criterion. The calculated criterion is given first, then the associated keys and values (components). Note that one has no possibility here to modify the coordinate system wrt which the components are expressed.

"DynamResExtract" worksheet

The "DynamResExtract" worksheet allows the extraction of XDB complex results for SOL 108 and SOL 111 analyses. The differences with "ResExtract" worksheet can be summarized as follows:

You no longer specify a sub-case. Indeed, the VBA function associated to "Extract" button extracts the results for all the sub-cases associated to the selected load case.
The extracted results are pasted into the spreadsheet in magnitude-phase format. Each component is saved in two columns by order of increasing frequency.
Two graphics are created:

The first one plots curves of the magnitudes versus frequency.
The second one plots curves of the phases versus frequency.

"GroupEdit" worksheet

When performing extractions, it can be very frustrating to discover that the group you need is not defined in the current database because it is not defined in the Patran session file you have read in the "FemDbIds" spreadsheet. The "GroupEdit" spreadsheet has been added to allow the user to define new groups, or modify existing groups during an excel session.

The spreadsheet has several capabilities:

A Combo box allows to select a group already existing in the database. The corresponding group name is then written in cell C3.
You can also fill the cell C3 manually. Actually, you have to do it for the definition of a new group that does not exist in the database.
You can define lists of FEM entities in the range "A11:E***". Entities are specified by their type, a single ID, or an ID range.
Three buttons allow to add (or replace) a group in the database, add entities to an existing group, or remove entities from an existing group. The removed or added entities are specified in range "A11:E***".

The data and controls in range "I1:N7" can be used to define new groups by topological operations.

If you want to save created groups for a later usage, you can export a Patran session file by clicking the corresponding buttons in "FemDbIds" worksheet.

References

More information on this example, and the manual explaining the functions used in this example are given in FeResPost Reference Manual.

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