VES App Note #9
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X coord = 10
Y coord = 5
X coord = 0
Enter “Orientation Point” in the Label field of the new Point.
To hide this Point so it will no longer be displayed,
Drag the vertical blue bar to the left to expose the FEA Bars spreadsheet. Double click on the FEA Properties column heading, and select Bar 1 from the list in the dialog box that opens.9.9e6 Double click on the Orient Point column heading, and enter “7” into the dialog box that opens.
To add the FEA Bars to the centerline Substructure,
Click on the Visible cell for the orientation point, changing its entry to No.
To add this Point to the centerline Substructure,
25-Feb-14
Make sure that Point 7 is selected. Execute Draw | SubStructure | Add Selected Objects to Substructure in STR: Free-Free Beam. Select the Editable Line in the dialog box that opens, and click on Add To.
This completes the definition of the orientation point.
Make sure that the five FEA Bars are selected. Execute Draw | SubStructure | Add Selected Objects to Substructure in STR: Free-Free Beam. Select the Editable Line in the dialog box that opens, and click on Add To.
CALCULATING THE FREE-FREE MODES Now that the FEA beam has been completely defined, its free-free modes can be calculated.
Next, the 5 FEA Bars will be added to the model between the 6 centerline Points.
NOTE: All modes depend on the boundary conditions on a structure. Free-free modes reflect a condition where there are no constraining boundary conditions at both ends of the beam.
ADDING THE FEA BARS
Right click in the graphics area of STR: Free-Free Beam, and execute Object List | FEA Bars. Right click in the graphics area, and execute Add Objects. Click near the Point at the end of the Line, and then near the Point adjacent to it to add the first FEA Bar element between these two Points. Keep clicking down the centerline to add all five FEA Bars, as shown in Figure 6. Right click in the graphics area again, and execute Add Objects to terminate the Add FEA Bars operation.
Execute FEA | Calculate FEA Modes in the STR: Free-Free Beam window. Click on Yes in the dialog box that opens, enter parameters into the next dialog box, as shown below, and click on OK.
After the modes have been calculated,
Click on the New File button in the dialog that opens, and enter “free-free modes” into the next dialog box.
A new Shape Table window will open listing the free-free modes of the beam, as shown in Figure 7. Figure 6. FEA Bars Added to the Centerline. Properties & Orientation Point The final two steps needed to define the FEA model are to assign the FEA Properties and the Orientation Point to the 5 FEA Bars.
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