WORKSHOP 6 NESTED COORDINATE SYSTEMS презентация

satellite model. Rotate the position of the satellite payload relative to a spacecraft platform using nested coordinate systems.

input file antenna.bdf.
Note the existing coordinate systems.
Export a .bdf file from Patran.
Review the .bdf to see that the coordinate systems are not nested.
Change the translation parameters in Patran and export another .bdf file.
Review the second .bdf file to ensure that the coordinate systems are nested.
Modify the .bdf to rotate the antenna assembly 90 degrees so that the X axis of coord 390000 is aligned with the basic Y axis.
Save the .bdf file.
Open a new database in Patran.
Import the modified .bdf.
View the rotated model.
Explore additional transformations using coord 390003

as the file name.
Click OK.
Choose Default Tolerance.
Select MSC.Nastran as the Analysis Code.
Select Structural as the Analysis Type.
Click OK.

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MSC.Nastran Input.
Select the file antenna.bdf.
Apply.

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defines the position of the base and is defined relative to Coord 0.
Coord 390003 defines the position of the dish and is defined relative to Coord 390000.

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Analysis Deck.
Enter default_translation as the Job Name.
Click Apply.

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end of the file. Note that field three is blank, which defaults to the basic coordinate system.

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nested coordinate systems.
Analysis: Analyze / Entire Model / Analysis Deck
Change the job name.
Click Translation Parameters.
For Coord Frame Coordinates, set the value to reference frame.
Click OK.
Click Apply.

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390003 now references Coord 390000.

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rotate the antenna assembly 90 degrees.

Since Coord 390003 is nested, we will only need to modify Coord 390000.
The X Axis of Coord 390000 should be rotated to align with the basic Y Axis.
One possible modified coordinate system is shown below.

Modified .bdf:

Original .bdf:

to rotate the coordinate systems.

as the file name.
Click OK.
Choose Default Tolerance.
Select MSC.Nastran as the Analysis Code.
Select Structural as the Analysis Type.
Click OK.

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f

d

c

g

MSC.Nastran Input.
Select the file rotated_antenna.bdf.
Apply.

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base have been rotated.

and translational changes to the coordiaate systems and view the resulting displacements in Patran.