Instructions for Running SectionBuilder

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

5
Running the Dbox Demo

• There are several different dbox demo files

• 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

6
What You Should See Next

• Click on the Mesh button to read the input file.
• This will cause the FEM button to be highlighted.

3. Click on the Disk icon to save the current
model.
Do not use any other menus before clicking the
Mesh button!
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.
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
2. Enter the dimensions for the Top left flange
here. See the SectionBuilder manual for details
of section geometry.
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

• Choose Materials tab.
• Click buttons to define material for a region of
  section.

• 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

• Use pull-down menu to select one of the
  predefined Materials.
• Click OK (both windows).
• 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

• Choose Loading menu.
• Select loading to edit (or create a new loading).

• Click Applied moments to edit.

• Edit the M1 moment.

Scaling factor has the same effect
Be careful to not define inconsistent sectional
loadings

• Click OK (3 times).

15
What You Should See Next

• Click the Disk button to save the model.

• Next, click the Mesh button to re-mesh the model.

16
Running the Analysis

• 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

• Next, click the Visualize button to display the
  model and analysis results.

19
The Visualizer Window
Output display selection
Loading selection
Visualizer controls
Current loading in Visualizer
20
Displaying Principal Axes/Centers
Display Principal Axes and cross section centers
B bending centroid S shear center I
center of mass, moments of inertia
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 x1 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 x1
  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
Same controls are in Graphics menu.
Visualizer controls used to rotate section in
order to see warping.
Use Ctrl-? or Ctrl-? to adjust display amplitude.
25
What is a Reserve Factor?

• Failure conditions can be written as f(s)1 where
  s represents the stress state at a point and f(s)
  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 s)1
• r gt1 implies failure has not occurred at that
  point
• r lt1 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 elements border.
• Finally, click Display Element Stresses.

Display a field (t)
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 elements 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 shouldnt 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_at_gatech.edu
• Office ESM G-10,
• Hours Mon 12-1 Wed 2-3