WS12-1 VND101, Workshop 12 MSC.visualNastran 4D Exercise Workbook Bike Release Lever

WS12-1VND101, Workshop 12

MSC.visualNastran 4D

Exercise Workbook

Bike Release Lever



ObjectivesDetermine the factor of safety based on von Mises stresses with minimum factor of safety =1.

Target stress calculation error to 10%

Exercise Overview Import model from various CAD

applications. Set Unit system to English. Apply material to Aluminum 2024-T3. Load the underside of the lever with a

total force of 30 pounds. Restraint the part as bolted through the

hole. Verify initial results. Target results with H-Adaptivity. Display results.


Figure 1 Opening file

Figure 2 Unit selection

I - Open New File / Import Part

1) Open the part called bikereleaselever.SAT or bikereleaselever.x_t . (Figure 1)

If you are working with the following CAD package: SolidWorks, Solidedge, or Mechanical Desktop, you can also open the Bracket in the native CAD environment and Connect the part over.

2) If the ACIS Import Settings window appears, choose “Override units” and pick in (inches) from the pull-down. (Figure 2)

3) Click “OK”.

Once you click “OK”, the bike release lever is imported into visualNastran4D.


II - Unit and Material Specification

Besides the initial selection of units during the opening of a file, units may also be selected as follows:

3) Pick Display Settings from the World menu or the Display Settings tool from the toolbar.

The Settings dialog box will appear.

4) Pick the Units tab, and choose “English (pounds)” from the Unit System pull-down. (Figure 3)

5) Click “Apply” and “Close” to close the Settings dialog box.

Figure 3 Display Settings


5) To specify the material, double-click the “bikereleaselever” in the Object List or in the Simulation Window.

The Properties dialog box appears.

6) Go to the Material tab. (Figure 4)

7) Click “Change” and in the Material Properties page, specify “Aluminum 2024-T3” as the desired material for the bikereleaselever. (Figure 5)

8) Click “OK” to close the Material Properties dialog box.

9) Click “Close” to close the Properties dialog box.

Figure 4 Material Tab

II - Unit and Material Specification

Figure 5 Material Properties Page


Figure 6 Rotated view

III - Apply Load and Restraint

9) Click the “Rotate Around” button and rotate the release lever so that the bottom of it can be seen. (Figure 6)

10) To apply a load, select the Insert pull-down and choose Structural Load or click the Structural Load tool from the toolbar.

The curser changes from an arrow to two arrows to represent a structural load.

11) Pick the bottom face of the release lever to apply the load. (Figure 7)

The face will be highlighted black and the curser turns into a sheet of paper symbolizing the load will be placed on the whole face. (Figure 7) After applying the load, the face will be outlined with the green arrows.

Figure 7 Bottom Face


Figure 9 Structural Load Tab


12) To specify the load value, right click on “constraint[3]” in the Object List and choose Properties. (Figure 8)

This is the constraint just created. The Properties dialog box appears.

13) Pick the Structural Load tab. In the “Type” field, choose Total force. (Figure 9)

14) Key in “30” for the y-direction, set the x and z directions to “0”, and click “Apply”. (Figure 9)

Make sure “Body” is selected for Frame and “Cartesian” is selected for Coordinates.

15) Go to the Appearance tab and rename the constraint[3] to “Load”. Accept the default color (green) and click “Apply” and “Close” to close the dialog box.

Note that the “Appearance” tab is visible if it is checked in the Properties List.

Load symbols now appear on the part as shown in Figure 10.

Figure 8 Properties


Figure 10 Applied Load



Figure 12 Applied Restraint


15) Use the Rotate Around and zoom tools to get the desired view that is similar to Figure 11.

16) To specify restraints, select the Insert pull-down and choose Restraint or click the Restraint tool.

17) Pick the bottom half of the internal face of the hole.

Blue crosses now appear outlining the bottom half of the internal face of the hole. (Figure 11)

18) Repeat these last two steps to place a restraint on the top half of the internal face.

19) Zoom out and rotate the model so it appears similar to Figure 12.

With the new restraints and loading, your workspace should now resemble Figure 12.

The hole should be restrained in all x, y, and z directions. To ensure this is true, right click on the constraints and pick Properties. Then pick the Restraint tab and confirm.

Figure 11 Select Internal Faces


Figure 13 Simulation Setting – FEA Accuracy

Figure 14 Simulation Setting – FEA

IV - Analysis Setting

Before running the analysis, we must set the simulation to produce the desired results. Once again, the objective of this exercise is to determine the factor of safety based on von Mises stresses (minimum factor of safety =1) and allow a 10% stress calculation error.

18) From the World menu, choose Simulation Settings. Go to the Accuracy tab under the FEA tree.

19) In the “Result Verification” area, check “Test result validity”. Check “Test mesh quality” and key in “10” for Max error percent. Then check “Test design intent” and key in “1” for Min factor of safety. (Figure 13)

20) Then make sure that “H-Adaptivity” setting is not checked. (Figure 13)

21) Finally, select the FEA tab and make sure “Stress” is checked as the Analysis type. Accept all other defaults. (Figure 14)

22) Click Close.


Figure 15 MSC.Nastran progress meter

Figure 16 Events indication window

V - FEA Analysis

22) To begin the FEA analysis of the release lever, click the “Solve FEA” gyro at the bottom of the visualNastran Desktop window in the Playback Controls.

After the analysis begins, the MSC.Nastran “progress bar” appears to display the status of the process. Keep this progress meter open while the analysis is running as shown in Figure 15.

The Events indication window appears as shown in Figure 16. It indicates that linear-elastic test and the factor of safety test passed. However, the mesh quality test failed and suggests using H-adaptivity to refine the mesh.


Figure 17 - FEA Accuracy

Figure 18 H-Adaptivity Goal Obtained

VI - Refine Results

23) Return to the Simulation Settings dialog box through the World menu and pick Accuracy under FEA.

24) Check “H-Adaptivity” and key in “3” Max iterations. Also set “Target error” to “10%”. (Figure 17)

25) Click “Apply” to activate the changes.

26) In the Tolerance tab under the Simulation Settings tree, accept the default “Bond Tolerance”. Click Close.

27) Click on the new “Solve FEA” gyro in the playback controls and observe the analysis go through 3 iterations. (Figure 17a)

28) The analysis is completed when the “H-Adaptivity Goal Obtained” window appears.

The result from H-Adaptivity shows that maximum error was 6.26% after a total of 2 iterations, shown in Figure 18.

Figure 17a “Solve H-Adaptive FEA”


Figure 20 Properties List

VII - Display Results

28) Mesh, Deformation, Contours and Computed forces can be shown either by:

- Right-clicking on the “bikereleaselever” in the object list, picking Properties, going to the FEA Display tab, and then clicking on the three boxes shown. (Figure 19)

If “FEA Display” does not appear in the Properties window, click on it in the Properties List in the Lower Left hand corner. (Figure 20)

OR

- Right-clicking on the body in the drawing area and picking Show Mesh and Show Deformed from the resulting pop-up menu. (Figure 20a)

29) Click Close.

30) The results are shown in the Simulation Window. (Figure 21)

Figure 19 FEA Display

Figure 20a - Right-click pop-up menu.


Figure 21 Results

VII - Display Results

31) Click the arrow next to the “Run” button, choose Animate FEA from the pop-up. (Figure 21a)

32) Press this new run button to view the static stress simulation.

It will run through the iterations at every frame at animate each frame.

This exercise is now complete.

Figure 21a “Animate FEA” play button


ReviewYou learned to determine the factor of safety based on von Mises stresses with minimum factor of safety =1.

Restraint the part as bolted through the hole.

Verify initial results.

Target stress calculation error to 10% with H-Adaptivity.

Display results.

Documents

WS12-1 VND101, Workshop 12 MSC.visualNastran 4D Exercise Workbook Bike Release Lever