Structures containing long, constant cross-section beams can be modeled efficiently in Pro/MECHANICA by using beam elements rather than solid elements.  In this tutorial, you will learn how to construct and analyze beam structures. 

1. Start Pro/E Wildfire.
2. Select [File] -> [New], type the part name [Bridge] in text box, and click the OK Button.
3. You will begin by defining the nodes of the structure.  Select the Sketched Datum Point icon from the tool bar at the right of the screen, as shown in Figure 1.1.

   
   [Figure 1.1]

    

4. Select the reference plane marked as FRONT.
5. Click the Sketch button from the Sketched Datum Point window.  Pro/E will switch to Sketch Mode.
6. Select [Sketch] -> [Options] from menu bar.  Turn ON the [Grid] and [Snap To Grid] in the Sketcher Preferences window and click the green check button.
7. Select the Create Points icon , and click on the 8 points circled in red in Figure 1.2 to define these as nodes.  You will should draw them in the order shown so that your points are labeled consistently with the ones shown in the figures of this tutorial.  You may need to pan and zoom to get the correct view.
8. Make sure the dimensions of the points are the same as those shown in gray the figure.  If not, click on the Select Icon and change the incorrect dimension by double clicking on it and typing the correct value.

   
   [Figure 1.2]

    

9. Select the Continue icon from the tool bar at the right of the screen to exit Sketch Mode.  You should see the points as shown in Figure 1.3.

   
   [Figure 1.3]

    

10. Select [Edit] -> [Feature Operations] from the menu bar.
11. Select [Copy] -> [Move] from the Menu Manager, and then select [Done].
12. Click on one of the points you just created, which will select them all, and select [Done] from the Menu Manager.
13. Select [Translate] and then [Csys], and click on the coordinate system in the model window.
14. Select [Z Axis] and then [Okay]. 
15. Enter an offset distance of 90 in the text box at the bottom of the screen, and click the check button.
16. Select [Done Move] and then [Done] from the Menu Manager. 
17. Select the OK button from the Group Elements window, and select [Done] from the Menu Manager.  You should see a second set of points as shown in Figure 1.4.

    
    [Figure 1.4]

     

1. Select [Applications] -> [Mechanica] from the menu bar.  A window will be displayed containing the unit information for the assembly.  Note the units displayed, as all analyses you will perform will not show units, and click the Continue button on this window.
2. Make sure the FEM Mode button is unchecked on the Menu Manager.  If you cannot uncheck it, you will need to modify the installation of Pro/E.
3. Select [Structure] -> [Idealizations] -> [Beams] -> [New] from the Menu Manager.
4. In the Beam Definition window, click the arrow button under References so that you can select the two points defining the start and end of the first beam.
5. Select the points labeled Pnt0 and Pnt5 in Figure 1.4 (the labels for your points may be different than the ones shown in the figure, depending on the order in which you drew the points).
6. Now you will define the material of the beam.  Select the More button next to Material. 
7. Select [Steel] from the Materials in Library list, and click the Assign Material icon .  Click the OK button.
8. Now you will define the beam orientation (for more information on beam orientations, see the Pro/E help files).  Leave Y Direction set to WCS (world coordinate system), and set X to 0, Y to 1, and Z to 0.
9. Now you will define the cross-section of the beam.  Select the More button next to Section.
10. Select the New button from the Beam Sections window.  Change the name to [main_supports]. 
11. Change the type to [Hollow Circle], and set the outer radius to 2 inches and the inner radius to 1.5 inches, as shown in Figure 1.5.

    
    [Figure 1.5]

     

12. Click the OK button from the Beam Section Definition window and the Beam Sections window.  The Beam Definition window should look like the one shown in Figure 1.6.

    
    [Figure 1.6]

     

13. Click OK to close this window.  You should now see the beam shown in blue in Figure 1.7.

    
    [Figure 1.7]

     

14. Select [New] again from the Beam menu of the Menu Manager.
15. In the Beam Definition window, click the arrow button under References.  Select the points labeled Pnt5 and Pnt6 in Figure 1.7.
16. Make sure the material is set to STEEL and the section is set to main_supports.  Set the Y direction vector (X, Y, Z) to (0, 1, 0) as you did for the first beam.
17. Click the OK button to create the beam.
18. Repeat steps 14 - 17 to create the main supports of the bridge, as shown in Figure 1.8.  To make the process easier, you can change Reference in the Beam Definition window to [Point Point Pair] and select the endpoints of all the beams at once.  To do this, hold down the Control key and select the start and then the end of each beam segment.

    
    [Figure 1.8]

     

19. Now you will define the cross-beams of the bridge.  These beams will have a different cross section than the main supports of the bridge.  Select [New] from the Beam menu again.
20. Select the More button next to Section, and select the New button from the Beam Sections window.
21. Call the new section [cross_beams], and change the type to [Hollow Circle].  Set the outer radius to 1.25 inches and the inner radius to 1.00 inches.
22. Click the OK button from the Beam Section Definition window and the Beam Sections window.
23. Using this cross section instead of the one for the main supports, add the beams shown in Figure 1.9.  Use a Y Direction vector of (0, 0, 1).

    
    [Figure 1.9]

     

24. Add the beams shown in Figure 1.10.  The cross section of these beams should be cross_beams and the Y Direction vector should be set to (0, 1, 0).  Figures 1.11 and 1.12 show the top and front views of what the final bridge should look like.

    
    [Figure 1.10]

    
    [Figure 1.11]

    
    [Figure 1.12]

1. You will first constrain the ends of the bridge so that they cannot move.  Select [Done/Return] from the Idealizations menu, and then select [Constraints] -> [New] -> [Point].
2. Click the arrow button under Point(s).  Hold down the Control key and select the four endpoints, labeled as Pnt 0, Pnt 8, Pnt 4, and Pnt 12 in the figures above.  Click OK from the Select window.
3. Click the appropriate icon to set the Z Rotation to free, and leave all the other rotations and translations as fixed, as shown in Figure 1.13.  This will define a pin joint at the points.

   
   [Figure 1.13]

    

4. Select the OK button from the Constraint window.  You should see the constraints as shown in Figure 1.14.

   
   [Figure 1.14]

    

5. Now you will apply loads to the bridge.  Select [Done/Return] from the Constraints menu, and then select [Loads] -> [New] -> [Point].

6. Click the arrow button under Point(s).  Hold down the Control key and select the points labeled as Pnt 3 and Pnt 11 in the figures above.  Click OK from the Select window.
7. Set the Y Direction force to -10,000 lbs, and leave all the other forces and moments set to 0.
8. Select the OK button from the Force/Moment window.  You should see the forces as shown in Figure 1.15.

   
   [Figure 1.15]

    

9. You will now run a static analysis of the structure.  Select [Done/Return] from the Loads menu, and then select [Analyses/Studies] from the Mec Struct menu.

10. Select [File] -> [New Static] from the Analyses and Design Studies window.

11. In the Static Analysis Definition window, set the name of the analysis to Bridge_Static.  Make sure LoadSet1 and ConstraintSet1 are selected, and that the method is set to Multi-Pass Adaptive.  Select the OK button.
12. Select the Run icon on the Analyses and Design Studies window to begin the analysis.  Select Yes when asked if you want error detection.
13. This analysis should just take a minute.  You can view the progress by selecting the Display Study Status icon .
14. When the analysis is completed, select [Results] from the Menu Manager.  A new window should open.
15. Select [Insert] -> [Results Window] from the menu bar.
16. Click the icon under Design Study and select the analysis you just performed.  Set the display type to [Fringe], the quantity to [Stress], and the component to [von Mises].  Select the OK and Show button.  You should see the display shown in Figure 1.16.  You can rotate and translate this display using the same mouse commands that you would use to rotate a part when modeling it.

    
    [Figure 1.16]

     

17. You can insert more results windows to show other stresses, displacements, etc.  Select [Insert] -> [Results Window] again.  Select the same design study.  This time, set the quantity to Displacement and the component to Magnitude.  Under the Display Options tab, check the Deformed checkbox.  Click the OK and Show button.  You will see the displacement of the bridge, as shown in Figure 1.17.  Notice that the displacements are greatly exaggerated, with the scale at the right indicating actual displacements.

    
    [Figure 1.17]

     

18. You can change the cross-sections of the beams to see how it affects the stresses in the bridge.  Close the results windows and select [Model] -> [Idealizations] -> [Beams] -> [Sections] from the Menu Manager.

19. Select the beam section main_supports, and click the Edit button.

20. Change the Section Type to I-Beam, and set the values to the ones shown in Figure 1.18.  These are the properties of a W6 X 9 Wide Flange I-Beam.

     
    [Figure 1.18]

     

21. Select the OK button from the Beam Section Definition window and close the Beam Sections window.
22. Select [Done/Return] from the Idealizations window, and then select [Analyses/Studies] from the Mec Struct menu.
23. Select [File] -> [New Static] from the Analyses and Design Studies window.
24. In the Static Analysis Definition window, set the name of the analysis to Bridge_Static.  Make sure LoadSet1 and ConstraintSet1 are selected, and that the method is set to Multi-Pass Adaptive.  Select the OK button.
25. Select the Configure Run Settings icon .  Under Elements, select the radio button for Create Elements During Run.  Otherwise, the analysis would use the same beam elements (with circular cross-sections) that were used in the first analysis.  Select the OK button.

26. Repeat steps 12 - 17 to run the new analysis and plot the results.  You should see the results windows shown in Figure 1.19.

    
    [Figure 1.19]