Transcript tutorial

Instructions for Running
SectionBuilder
O. A. Bauchau
J. I. Craig
AE3125 Spring 2007
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…
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!
Demo Choices
Open the folder
corresponding to
the type of section
you wish to
analyze:
Airf
Airfoil
Dbox Two-Cell Box
Tria
Triangular Section
Carc
Circular Arc
Isec
I-Section
Tsec
T-Section
Csec C-Channel
Rbox Rectangular Box
Tube
Circular Tube
Cyld
Rect
Solid Circular
Cylinder
Solid Rectangular
Section
Running the Dbox Demo
1. 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
What You Should See Next
3. Click on the Disk
icon to save the
current model.
Do not use
any other
menus before
clicking the
Mesh button!
1. Click on the Mesh
button to read the
input file.
2. This will cause the
FEM button to be
highlighted.
Files that are Created
• Several files are
created on Save:
– .out
– .sbf.bak
– .sbg.bak
– .html
– .sva
• These files contain
setup info for now.
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.
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
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
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)
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)
Selecting Materials
1. Choose Materials tab.
2. Click buttons to define material for
a region of section.
•
Left Web Material applies to:
–
–
–
–
•
Right Web Material applies to:
–
–
–
–
•
•
Left Web
Top Left Flange
Bottom Left Flange
Left Wall
Right Web
Top Right Flange
Bottom Right Flange
Right Wall
Top Flange Material applies to top
reinforcement
Bottom Flange Material applies to
bottom reinforcement
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.
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…
5. Click OK (3
times).
Be careful to not
define inconsistent
sectional loadings
What You Should See Next
1. Click the Disk button to save the
model.
2. Next, click the Mesh button to remesh the model.
Running the Analysis
1. Click the FEM button to run the
computational analysis.
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
What You Should See Now
1. Next, click the Visualize button to
display the model and analysis
results.
The Visualizer Window
Loading
selection
Output display selection
Visualizer
controls
Current loading in Visualizer
Displaying Principal Axes/Centers
Display Principal Axes and cross section centers
B = bending
& centroid
S = shear
center
I = center of
mass,
moments
of inertia
Selecting Field to Visualize
Display warping, strains, stresses, reserve factor
Notes on Field Outputs
• Stresses and Strains
– Displayed as vectors
– In-plane quantities will appear in-plane, and out-ofplane 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)
Example – Visualizing Warping
w/out Rotating Viewport
Warping displacement is in x1 direction
(perpendicular to viewing plane)
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.
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
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 (t)
Element selection
Display element stresses
An Example
Note highlighted element
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
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
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
What the .OUT File Looks Like
• This file contains the execution log
Sensor Output
• The sensor output appears in the test.sbs file (in this
example there are other sensors you can scroll through):
Stiffness/Compliance Matrices
• This output appears in the test.sbp file (in this example there are
other sectional properties you can scroll through):
Stiffness/Compliance Matrices
• The full sectional stiffness and compliance matrices are
also available.
Applied Sectional Loads
• This output appears in the test.sva file and can be
used to confirm your applied loads.
More Output
• Also, you can find location of the various crosssectional centers
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.
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:
– [email protected]
– Office: ESM G-10,
– Hours: Mon 12-1 & Wed 2-3