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WS09-1 VND101, Workshop 09 MSC.visualNastran 4D Exercise Workbook Belted Cylinder
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WS09-2 VND101, Workshop 09
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WS09-3 VND101, Workshop 09 Objectives Open a.wm3 file that has all the constraints already built in. The purpose of this exercise is to control the actuators in ways that they will lift the cylinder evenly. Insert sliders to control the actuators. Manually move the sliders one at a time to as the simulation is running to achieve the motion that you want. Play with the sliders until you get a controlled motion as the cylinder is being pulled up. Utilize tables to get a control motion. Exercise Overview Open visualNastran File. Create a rigid joint. Insert meters. Add sliders. Measure lengths. Input data onto meter. Export data from meters. Insert table input. Run simulation.
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WS09-4 VND101, Workshop 09 Introduction In this exercise, you will learn how to use input sliders and input data to control your simulations. Input sliders are controls that allow you to dynamically change the properties of the objects in your simulation as it runs. Unlike sliders, input table is not an interactive control. Instead, tables contain dependent and independent variable data.
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WS09-5 VND101, Workshop 09 I - Open File 1)Open the associated Belted Cylinder.WM3 file. Figure 1 Open file
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WS09-6 VND101, Workshop 09 II - Create a Rigid Joint 2)Click the Simulation Settings tool from the toolbar or from the World pull-down menu. The Settings dialog box will appear. 3)Click on the Integration tab in the Simulation Settings tree. The Settings tree is located on the left side of the dialog box. The Settings dialog box will show the Integration page when it is clicked. (Figure 2) 4)In the “Integration” page, change the “Animation Frame Rate” to “20 frames per second”. (Figure 2) 5)Click “Apply” to apply this change. Notice that the “Time” field changes after changing this value. 6)With the MSC.visualNastran Desktop Settings open, go to the Numbers tab under the Display Settings tree. Now, the Settings dialog box shows the Numbers page. 7)In the “Number Display” area, click “Automatic” and change the significant digits to “3”. (Figure 3) 8)Click Apply. You can click on the “Fixed Point” and “Floating Point” options and view how the numbers will be displayed in the “Example” area. (Figure 3) 9)Close the Settings Window. Figure 2 Integration Tab Figure 3 Numbers Tab
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WS09-7 VND101, Workshop 09 II - Create a Rigid Joint 10)Double click on the left actuator (constraint[293]). The Properties dialog box will pop up. 11)Go to the Appearance tab. (Figure 4) 12)Type “Left Actuator” in the “Name” field and click “Apply”. (Figure 4) 13)Go to the Actuator tab to see the value assigned. The Left Actuator has a value of 25 inches assigned to it. (Figure 5) 14)Close the Properties dialog box. 15)Repeat steps 10 through 14 and assign the names for the “Right Actuator” and “Top Actuator”. Figure 5 Actuator Tab for Left Actuator Figure 4 Appearance Tab For Left Actuator
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WS09-8 VND101, Workshop 09 II - Create a Rigid Joint 16)Run the assembly to see the behavior of the assembly. You will notice that the value assigned to the actuator does not give the motion that we want, which is to lift the cylinder above the ground and over to the right in one swift motion. Figure 6 Belted Cylinder
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WS09-9 VND101, Workshop 09 III - Insert Meters 17)Select an actuator, and under the Insert pull-down menu, click Meter>Constraint Length. (Figure 7) 18)Click “Tile Vertically” in the resulting pop-up menu. 19)Repeat the last two steps for the other two actuators. Your visualNastran window should now look like Figure 8. Figure 7 Constraint Length Figure 8 Add Three Meters
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WS09-10 VND101, Workshop 09 IV - Add Sliders We will use length actuators. 20)Go to the Object List manager and click on “Left Actuator”. (Figure 9) 21)With the constraint highlighted, go to Insert>Control>Length. 22)Choose “Slider” when the Input Type window is prompted and click “OK”. (Figure 10) An input slider like the one in Figure 11 appears in a separate floating window. 23)Double click on the gray part of the slider you just created. A properties dialog box will appear. 24)In the Appearance tab, change the name to “Slider for Left Actuator” and click “Apply”. (Figure 12) Figure 10 Input Type Figure 9 Object List Figure 11 Slider Figure 12 Appearance Tab
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WS09-11 VND101, Workshop 09 IV - Add Sliders 25)Go to the Input Tab. 26)Change the min and max value to “10” and “100”, respectively. (Figure 13) 27)Click “Apply” and “Close” the Properties dialog box. 28)Repeat steps 15 to 21 for Right Actuator. Name it “Slider for Right Actuator” with the same min and max values. 29)Repeat steps 15 to 21 for Top Actuator. Name it “Slider for Top Actuator” with min and max value of 0 and 55, respectively. The Input page for the Top Actuator is shown in Figure 14. Figure 13 Input Tab for Slider for Left Actuator Figure 14 Input Tab for Slider for Top Actuator
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WS09-12 VND101, Workshop 09 V - Measure Lengths 30)To check to see the current length of the actuators, first click the plus sign next to the constraint in the Object List Manager. 31)Using the control key, select the two coords under the constraint. 32)Right-click on either coord and select Show from the pull-down menu. 33)Click on the “Distance Dimension” icon in the annotation toolbar. 34)Using the “Box Zoom” and “Rotate Around” tools, select one coord, move the mouse to the other coord and left-click once. (Figure 15) Find the current length of all three actuators. Notice that the bottom two actuators have a fixed length of 69 inches and the top actuator has a fixed length of 49 inches, as shown in Figure 16. 35)Use those values and enter it in the appropriate slider so the actuator is at rest when you run the simulation. Refer to Figure 17. Figure 15 Actuator Figure 16 Current Lengths
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WS09-13 VND101, Workshop 09 VI - Table Input Ideally, you would want to have the actuators operate simultaneously to perform a smooth uniform motion. However, since all the slider controls are independent, only controlling the motion manually will most often not accomplish this. To accomplish this, we will need to perform the movement manually, and then modify and manipulate the exported values so they are running at the same time slot, thus controlling the motion of the actuators simultaneously. 36)Run the simulation and slowly move each actuator up and over to the right by moving each slider to the left and minimizing the actuator. All the movements of the simulation will be recorded. You will notice that only one actuator is moved at a time so the action of the actuator is sequential. If you have difficulty controlling the sliders, open Belted Cylinder_Sliders.wm3 file. This file contains the simulation with recorded history when the sliders were moving. 37)Once you get the cylinder to a steady position, stop the simulation. 38)Replay the simulation to see the movements that you manually controlled. Figure 17 Sliders Figure 18 Manually Move Sliders
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WS09-14 VND101, Workshop 09 VII - Export Data from Meters Remember not to erase the history of the simulation. Erasing it will get rid of all the recorded motion. 39)To export data from a meter, under the File pull- down menu, pick Export/Meter Data. 40)Give a file name, save it as Excel file. Choose “100” as the last frame it records. Change Digits to “5”. 41)After it is done exporting, it will prompt you to view the file. Click “Yes”. Figure 19 Export Meters
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WS09-15 VND101, Workshop 09 VIII - Link Timeslot Figure 20 Excel – Control Data (Before) As shown in Figure 16, the three actuators do not start moving at the same time. We need to link the timeslots so that all the actuators are moving simultaneously. This is done by selecting data where the actuators start to move and move it up where the time slot is the same. 42)Highlight the cells when the actuators starts to move and drag it up to the top getting rid of the data where the actuators is at rest. Your results should look like Figure 21 or Control Data.xls in C:\Training Files\Belted Cylinder. Figure 21 Excel – Control Data (After)
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WS09-16 VND101, Workshop 09 IX - Insert Table Input Now that we have all the data needed to control the actuator simultaneously, we will paste those values into a table input for each actuator. 43)We no longer need the sliders and the meters created previously. Go to the “Inputs and Outputs” Tab, select all of them, and press the “Delete” key. (Figure 22) 44)Double-click on “Left Actuator” in the Object List Window and bring up its properties. 45)Go to the Actuator Tab. You will notice that it remembers it’s input ID from the slider. 46)Change the value to “69 inches”. 47)Click on the button to bring up the Edit Formula page. 48)Select the icon in the Edit Formula page. The pop-up window should look like Figure 23. 49)Use the icon to eliminate all the default values in the table. Figure 22 Inputs Outputs Tab Figure 23 Edit Table without Excel Values
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WS09-17 VND101, Workshop 09 IX - Insert Table Input 50)Go to the Excel page and copy the data for the left actuators. Copy the time and length values in the Left Actuator Columns, as shown in Figure 24. 51)Go back to MSC.visualNastran Desktop and paste the values into the table cells. Click on the asterisk to highlight the first box, then select the paste icon. 52)Click OK. This will create an input table with an ID number attached to the actuators, as shown in Figure 25. 53)Click OK to exit out of the Edit Formula Page. 54)Repeat steps 38 to 46 for the Right and Top Actuator, making the Top Actuator’s length 49. 55)Tab to the Object List in the Object Manager Window. Select the top body and press “Control + A” to select all the bodies in that list. Right- click and scroll to Properties. 56)Tab to the Velocity page and enter “0” in every field, as shown in Figure 26. Figure 25 Edit Table with Excel Values Figure 26 Velocity Tab Figure 24 Copy Data
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WS09-18 VND101, Workshop 09 X - Run the simulation Once all the table data are inserted to each actuator, run the simulation to see the results. 57)Click “Run” and observe the simulation. This exercise is complete. Figure 27 Simulation Results
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