MENG 421 Assignment 3

Ansys Graphics Mode

  MENG 421 | Class assignments | 1 2 3 4 5 6 8 9 10 11 12  

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In today's lesson you will see the power of Ansys graphical mode by creating, capturing, and printing the above figure. (Click the figure to enlarge it.) Today we will work in batch mode as we did last time. You will also learn how to use the Pan, Zoom, Rotate Tool. The Ansys code for today only has a preprocessor section to define the model. Check the bracket code to see that Shell93, an 8-node structural shell element is used. We will not apply a load.

Notice that today's problem is very different from the one you did last week. For that lesson, you found the displacements and stresses in an axially-loaded bar. Since the system was formed from two uniform bars, it was natural to put nodes and apply loads at the bar ends. That is, it was a discrete problem. By contrast, today's problem and the remaining lessons deal with continuous bodies that do not have natural nodes. For these problems, Ansys needs to create the elements. Sometimes you must help Ansys improve the element shapes. For example, you know from your Strength of Materials class that stresses can be triple around a hole. The finite elements need to be smaller and more numerous where stresses are rapidly changing. Look at the relative size of the elements around the holes in the above figure.

1. Getting started
   
   • Before going any further, do the four things you learned last time: check the screen resolution, check the size of your stored files, clear the Recycle Bin, and clear the Temp folder.
   • Also do a fifth that you learned the first day -- change Explorer so it shows more about your files.
   • Do these five things each time you log in.

2. Setting up IrfanView
   IrfanView (pronounced Ear-Fun-View or Ur-Fun-View) is a photo editor you can use for screen capture and graphics editing. The MS Photo Editor is better for editing, but it is not current available on the Tech PCs. Also it cannot make screen captures. Both are on the Mechanical Engineering computers. To make a shortcut to IrfanView, do the following.
   • Click the Start Menu and move up to Programs
   • Move right to get the next menu
   • Move up to the IrfanView folder
   • Move right to open the folder
   • Move over to the IrfanView shortcut with the red icon shown here
   • Right-drag the icon to the desktop, release the mouse button, and pick Copy
   • Left-drag the shortcut to the Start menu so you can easily start it
   • Put another copy in your Send To folder so you can easily edit a picture
     • In the Explorer left pane, open the C:\Documents and Settings folder
     • Open your account folder
     • Open the Send To folder
     • Right-drag the icon to the right pane of the Send To folder, release the mouse, and pick Copy from the menu
     • If not already there also add a Notepad shortcut to Send To folder

3. Setting up MS Photo Editor
   (Do this after it has been installed on the Tech computers in a few weeks(?).)
   The Photo Editor is a part of MS Office and so is available on the Tech PCs. You will use it to edit and print graphic files you have captured with LView. To make a shortcut to the Photo Editor, do the following.
   • In the left pane of Explorer, left-click the C:\Win folder (not the name).
   • Right-click the folder and pick Find.
   • Type the name photo and press Enter.
   • Right-drag the Photo Editor icon to the desktop and pick Create Shortcut Here.
   • Rename the shortcut to just Photo Editor
   • Left-drag the shortcut to the Start menu so you can easily start it.
   • Leave the Find window open for the next step.

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4. Copy the file bracket.a from the class directory
   • Last time you learned how to copy a file from the Class Files page.
   • See the Copying Prototype Files for more information.
   • Steer the Save As dialog box so it points to U:\win\Ansys
   • Check that the file named bracket.a is present in your Ansys folder.

5. Editing your Ansys File
   In this section you will edit the Ansys file Bracket.a.
   • Last time, you configured Explorer to edit your Ansys files with Notepad.
   • In Explorer, locate your Bracket.a file in the right pane.
   • Left-click the file to highlight it.
   • Double-click the file. If Win2000 remembered the association you set up last time, it will start Notepad and feed it your Ansys file.
     (If you use the same PC each week, there is a good chance that this will work.)
   • If not, right-click the file to get a menu
   • Move to Send To and move right to get another menu
   • Click Notepad
   • Make the following changes to your Ansys file
     • Put your name where it says Your name
     • Put MENG 421 and the date
   • Click the File menu and pick Save.
   • Close Notepad by clicking the X in the upper right corner. Alternatively, right-click the program on the taskbar and pick Close.

6. Setting the Ansys workspace
   Last time you configured Ansys to use the directory C:\WINDOWS\Temp for its workspace. You learned that Ansys creates very large work files that you do not need. And if Ansys puts the files in your own directory, you will soon be out of space. Be sure that you have configured Ansys to use C:\WINDOWS\Temp.

7. Running Ansys
   In this section you will run your Bracket file with Ansys in batch mode. In the last lesson you ran axial1 in batch mode too, but since it was a one-dimensional problem, the graphic was not very interesting.
   • Start Ansys with the Run Interactive Now icon.
   • Click the Ansys File menu at the upper left and pick Read Input from.
   • The Read File dialog box will show C:\WINDOWS\Temp since that is where you set the workspace. On the other hand, if another location is shown instead, Ansys is not set correctly. Go back to the previous assignment and reset Ansys to C:\WINDOWS\Temp.
     But, of course, your Ansys files are not stored there.
   • Steer Ansys to the location to your files at U:\win\Ansys.
     • Drop down the Drive list and pick U
     • Double-click the win folder
     • Double-click the Ansys folder
   • Highlight your Bracket.a file by left clicking.
   • Click OK to start running your program
   • Click Close when the calculations are done.
   • Your figure should look like this except for your name and the date.
   • Check that your name, the date, and the title appear on the figure.

8. Manipulating the figure in Ansys
   You can change the appearance of the Ansys figure by using a Zoom tool.
   • Click the Ansys task-bar button.
   • In the Utility Menu click PlotCtrls and pick Pan, Zoom, Rotate to open a useful tool shown at the right.
   • You can change the orientation and size of your figure with buttons in this tool. Click the four arrows to move the figure and the small and large dots to zoom out or in. Additional clicks repeat the command.
   • Slide your figure over the caption by clicking the left arrow twice.
   • Click the header of your plot window to bring your figure to the foreground.

9. Capture, edit, and print your figure with IrfanView
   In this section you will capture your Ansys figure from the screen, then can edit and print it.
   • Start IrfanView from a shortcut you made above.
   • When IrfanView starts up, press the C key to start the capture. You can also click the Options menu and pick Capture
   • There are three options for Capture area:
     • Whole screen
     • Foreground window
     • Foreground window - Client area.
     Check that the middle one, Foreground window is selected.
   • Uncheck Include mouse cursor
   • For Capture method, select Hot key (Ctrl-11).
   • Click Start and IrfanView temporarily disappears.
   • Click the header bar of the window you want to capture.
   • Press Ctrl-11, the Hot key and the captured window appears.
   • Crop the figure to just the bracket and the title by dragging with the mouse.
   • If the cropping box is wrong, adjust it by moving the pointer to the frame edge or just click and try again.
   • Click the Edit menu and pick Crop selection.
   • If you want to print this figure in color, skip over the next two lines.
   • To change the figure to gray scale, click the Image menu and pick Convert to Greyscale.
   • Click the Image menu and pick Negative.
   • Click the File menu and pick Print.
   • To print in color, select the Color printer (in Spear)
   • Click Print
   • The next screen shows a preview your figure in the upper-right corner. If the figure is too small or too large, change the size by clicking Scale and change the X-Axis and Y-Axis values (try 2.5).
   • Click Print

10. More use of the Pan, Zoom, Rotate tool
    Change your figure some more with the Zoom tool.
11. Click the Pan, Zoom, Rotate header to make it visible.
12. Click the small and large dots to zoom out or in. Additional clicks repeat the command.
13. Try the Top, Front, Iso, Obliq buttons.
14. Reduce the size with the small button, then click the Box Zoom button. With the mouse, drag a zoom window across the figure, and click to enlarge.
15. With the Fit button at the bottom, you can just fill the screen with the object if it the wrong size.
16. Close the Pan window.

17. Help
    Extensive Ansys help is available by clicking the Help menu.
    • Pull down the Help menu and pick Help Topics.
    • Click the Contents tab.
    • Click the plus next to Element Reference.
    • Click Element Library.
    • Scroll the right pane down to SHELL93, the element we used today.
    • Click on SHELL93 to learn more about it.
    • Click the Back arrow of the Online Documentation dialog box and pick the PIPE16 to learn more about the element you used last time.
    • As you learned last time, all the element types we will be using can be found here.

18. To close Ansys
    • Click the Quit button on the Toolbar.
    • Click the circle next to Quit - No Save
    • Click OK
    • Remember, if you want to start up Ansys again, choose the Run Interactive Now icon.

19. Watching Your Storage Space (This doesn't work right now)
    
    • As you know, you need to keep an eye on the amount of files that are saved to your account.
    • Ansys stores several very large work files that you do not need to keep.
    • When you set the Ansys workspace to the C:\WINDOWS\Temp directory rather than to your own space you don't have to delete the Ansys work files before logging out.
    • Nevertheless, before logging out, check your account as you learned in Lesson 2.

20. Assignment
    Using a word processor, make a cover sheet describing what you did with Ansys. Point out how the finite elements are smaller around the holes where the stresses are greater. Discuss element types. Attach the Ansys code and the figure of the bracket with your name and date, and turn in the package as specified at the lab.

21. Before logging out check the size of your stored files.

Epilogue: In this lesson you learned how to run an Ansys batch program with interesting graphic output. You also learned how to capture the graphic, how to edit it, and how to print it. See my Photo Editing web page for examples of what you can do with photographs.

As with last week's lesson, you are not expected to understand all the Ansys code in Bracket.a. For now, your are learning how to run Ansys learn what it can do and learn a few Ansys commands. Later, you will begin programming Ansys from scratch. (See Assignment 9.)

  MENG 421 | Ansys -- Lecture 1 -- Class assignments | 1 2 3 4 5 6 8 9 10 11 12  
Files: Ansys, Matlab, Bash

Revised: March 19, 2004 -- Copyright © 1997-2004 ARMiller