1. Instructions for Running SectionBuilder O. A. Bauchau J. I. Craig AE3125 Spring 2007

2. Motivation Hand calculation of stress and shear flows on beam sections can be a tedious and time-consuming process very prone to errors… SectionBuilder is a program developed by Prof. Bauchau to numerically compute stresses and shear flows on beam cross sections. Because creating input files to analyze is also tedious, a collection of “templates” has been created. These template files parametrically define a number of common beam sections. By modifying the parameters in a template, you should be able to explore a wide range of beam cross section designs. NOTE: this is a first release of SectionBuilder and there are some interface problems that you may encounter; you will also have a limited number of options for now. These are being corrected…

3. Using SectionBuilder SectionBuilder is installed on all computers in the AE Computer Lab that have LCD screens. A read-only set of section templates is located in the AE3125 share and in C:\SectionBuilder\Demos. You should copy the Demos folder to a folder on your H: drive (i.e., H:\ae3125\work ). NOTE: you should not use spaces in the file names or unpredictable behavior may occur!

4. Demo Choices Open the folder corresponding to the type of section you wish to analyze: AirfAirfoilDboxTwo-Cell BoxTriaTriangular Section CarcCircular ArcIsecI-SectionTsecT-Section CsecC-ChannelRboxRectangular BoxTubeCircular Tube CyldSolid Circular Cylinder RectSolid Rectangular Section

5. Running the Dbox Demo First, double click clean.bat –Runs the batch file clean.bat –This clears out old unnecessary files Next, make a copy of dbox1.seb & dbox.sbf (BOTH files) –Right-click on the icons and drag to an open area in the window –Rename to your project, i.e., test.seb & test.sbf (make sure NOT to include any spaces in name) Double-click on the test.seb icon –This should bring up SectionBuilder –See the next slide 1.There are several different dbox demo files…

6. What You Should See Next 1.Click on the Mesh button to read the input file. 2.This will cause the FEM button to be highlighted. Do not use any other menus before clicking the Mesh button! 3.Click on the Disk icon to save the current model.

7. Files that are Created Several files are created on Save: –.out –.sbf.bak –.sbg.bak –.html –.sva These files contain setup info for now.

8. Modifying the Section 1.Pull down Sections menu and select Double box (all other choices should be grayed out) 2.Select dbox1 and press the Edit button. 3.Leave the name and Mesh Density alone, and select the Dimensions tab.

9. Modifying the Section 1.Click these 7 buttons to define the geometry of the section. 2.Enter the dimensions for the “Top left flange” here. See the SectionBuilder manual for details of section geometry. 3.Repeat for each of the buttons defining the section geometry. Click OK when done. For this particular section the following dimensions are required to be greater than zero: Left Web Thickness Right Web Thickness Web Height Top Left Flange Width See next slides for section geometry

10. What the Dbox Dimensions Mean Dimensions: A: Web Height (required) B: Top Left Flange (required) C: Top Right Flange Width (if set to zero, defaults to Top Left Flange Width) D: Bottom Left Flange Width (if set to zero, defaults to Top Left Flange Width) E: Bottom Right Flange Width (if set to zero, defaults to Top Left Flange Width) IMPORTANT NOTES: The coordinate system origin is located at the boundary between the left web and right web at 0.5*(Web Height) The x1 direction is axial, the x2 direction is horizontal, and the x3 direction is vertical

11. What the Dbox Dimensions Mean Dimensions: A: Left Web Thickness (required) B: Right Web Thickness (required) C: Top Left Flange Thickness (if set to zero, defaults to Left Web Thickness) D: Top Right Flange Thickness (if set to zero, defaults to Right Web Thickness) E: Bottom Left Flange Thickness (if set to zero, defaults to Left Web Thickness) F: Bottom Right Flange Thickness (if set to zero, defaults to Right Web Thickness) G: Left Wall Thickness (if set to zero, defaults to Left Web Thickness) H: Right Wall Thickness (if set to zero, defaults to Right Web Thickness) I: Top Reinforcement Thickness (if set to zero, reinforcement is omitted) J: Bottom Reinforcement Thickness (if set to zero, reinforcement is omitted)

12. What the Dbox Dimensions Mean Dimensions in degrees Sign Conventions indicated by arrows A: Top Left Flange Skew Angle (default zero) B: Top Right Flange Skew Angle (default zero) C: Bottom Left Flange Skew Angle (default zero) D: Bottom Right Flange Skew Angle (default zero)

13. Selecting Materials Left Web Material applies to: –Left Web –Top Left Flange –Bottom Left Flange –Left Wall Right Web Material applies to: –Right Web –Top Right Flange –Bottom Right Flange –Right Wall Top Flange Material applies to top reinforcement Bottom Flange Material applies to bottom reinforcement 1.Choose Materials tab. 2.Click buttons to define material for a region of section. 3.Use pull-down menu to select one of the predefined Materials. 4.Click OK (both windows). 5.Click OK to close Object selector window.

14. Changing the Loading You can edit, delete or create new sectional loadings using the Loadings menu and selecting Sectional Loads 1.Choose Loading menu. 2.Select loading to edit (or create a new loading). 3.Click Applied moments to edit. 4.Edit the M1 moment. Scaling factor has the same effect… Be careful to not define inconsistent sectional loadings 5.Click OK (3 times).

15. What You Should See Next 1.Click the Disk button to save the model. 2.Next, click the Mesh button to re- mesh the model.

16. Running the Analysis 1.Click the FEM button to run the computational analysis.

17. Analysis Results If everything worked, several files should have been created The files all have the same name (test) but with different extensions. They are all text files –.out = log file –.sva = loads file –.sbp = sectional properties –.sbs = sensor output file –.sbg = sensor names –.html = full input file

18. What You Should See Now 1.Next, click the Visualize button to display the model and analysis results.

19. The Visualizer Window Loading selection Current loading in Visualizer Visualizer controls Output display selection

20. Displaying Principal Axes/Centers B = bending & centroid S = shear center I = center of mass, moments of inertia Display Principal Axes and cross section centers

21. Selecting Field to Visualize Display warping, strains, stresses, reserve factor

22. Notes on Field Outputs Stresses and Strains –Displayed as vectors –In-plane quantities will appear in-plane, and out-of- plane will appear aligned along x 1 axis –Thus, the viewport must be rotated to see axial stress/strain vectors (use controls on screen right) Warping Displacements –Cross-sectional warping shape is shown –Therefore, as with axial quantities, the viewport must be rotated to see warping Reserve Factors –Reserve Factors are displayed aligned with x 1 axis (see note later on definition of Reserve Factor)

23. Example – Visualizing Warping w/out Rotating Viewport Warping displacement is in x1 direction (perpendicular to viewing plane)

24. Example – Visualizing Warping after Rotating Viewport Visualizer controls used to rotate section in order to see warping. Same controls are in Graphics menu. Use Ctrl-  or Ctrl-  to adjust display amplitude.

25. What is a Reserve Factor? Failure conditions can be written as f(σ)≥1 where σ represents the stress state at a point and f(σ) is a function of the stress state (e.g., von Mises stress). The reserve factor, is defined as the value, r, such that f(r σ)=1 –r >1 implies failure has not occurred at that point –r <1 implies failure has occurred at that point Note that when Reserve Factor is visualized in the Visualizer, r -1 is actually displayed –Higher values of r -1 indicate point is closer to failure –Output text file reports values of r, not r -1 Failure criteria are automatically supplied by SectionBuilder upon selecting a material

26. Querying Element Quantities First, click on one of the field selection buttons: –Clicking Displacements enables querying local displacements. –Clicking Axial Strains or Shear Strains enables querying local strains. –Clicking Axial Stresses, Shear Stresses, or Reserve Factors enables querying local stresses. Next, click Element Selection and then click on the element you wish to query. This should highlight the element’s border. Finally, click Display Element Stresses. Display a field (  ) Element selection Display element stresses

27. An Example Note highlighted element

28. Creating a Sensor Create a Sensor to send element values to the output file. Click Element Selection button and then click on the element you wish to attach a sensor to. This should highlight the element’s border. Next, click Create Sensor button. Element selection Create Sensor

29. Creating a Sensor In the Sensor dialog: –Enter a Sensor name –Select the Sensor output: stress, strain, or warping (displacement) –Select location in element where field variables are calculated Create as many sensors as you want/need Click Save (VERY IMPORTANT) You must run the complete analysis again for the sensor output to be included in the output file: –Click Mesh button –Click FEM button –Click Visualizer button

30. Opening the Output Files The SectionBuilder output is contained in several files. You can use your favorite text editor (i.e. Notepad) to open them

31. What the.OUT File Looks Like This file contains the execution log

32. Sensor Output The sensor output appears in the test.sbs file (in this example there are other sensors you can scroll through):

33. Stiffness/Compliance Matrices This output appears in the test.sbp file (in this example there are other sectional properties you can scroll through):

34. Stiffness/Compliance Matrices The full sectional stiffness and compliance matrices are also available.

35. Applied Sectional Loads This output appears in the test.sva file and can be used to confirm your applied loads.

36. More Output Also, you can find location of the various cross- sectional centers

37. Tips & Techniques The SectionBuilder interface is still being improved so you may encounter a premature program termination. This shouldn’t cause any harm or loss of data. Remember to Save your model whenever the Mesh, FEM & Visualizer buttons are grayed out. When making changes to loading or sensors or materials, you must Save the model, then click the Mesh, FEM and Visualizer buttons in sequence. Note that in such cases, the buttons are not always grayed out so make sure you click in order and wait a few seconds between clicks.

38. Seeking Help If you have any problems running SectionBuilder, getting it to do what you want, or encounter a bug: Contact the course TA: Waqas Majeed: –majeed.waqas@gatech.edumajeed.waqas@gatech.edu –Office: ESM G-10, –Hours: Mon 12-1 & Wed 2-3