ANSYS – Sample Beam Problem
Rev. 6/7/10
Preparation
Make a sketch of the structure
Choose your global reference frame
Number the nodes
Calculate the nodal coordinates
Calculate the section properties of each element: E, I, J, A, w and beam height h
Accessing ANSYS from Windows computers
Login / Password
(CAEDM Login)
Create a subdirectory for ANSYS
Start / Programs/CAD Programs/
Run RGS for Windows and login again
Start / Programs/CAD Programs/ ANSYS11X /ANSYS
Run ANSYS
ANSYS Setup
[PlotCtrls] >Zoom/Pan/Rotate
(drag this menu to the right of your workspace)
Open ANSYS Model File
[ ] = Top menu bar; > = Side menu bar
[File] >Change Directory
(change default directory)
[File] >Change Jobname
(enter name for new problem. Default: “file”)
Note! this will keep you from overwriting previous day's work)
[File] >Change Title
(enter title for new problem)
[File] >Switch Output to> jobname.out Note! Checkmark [√] Append box
[File] >Resume db jobname.db
(restore unfinished problem)
>Preferences
Select: Structural & h-method
(turns off thermal, electromag, fluid, Flotran menus)
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Create Model
Create Beam Model
>Preprocessor
(Click on menu item to expand menu)
>Element Type
>Add/Edit/Delete <Add>
Select: Beam 2D elastic
(create a group for each element type, cross section)
<Options…> K9 (5)
(outputs 5 intermediate points between nodes)
K6
(Include Output) <close>
>Real Constant
(define Iz, h for each size beam
>Add/Edit/Delete <Add>
A, Shrz, w are optional)
A=100, Iz = 10, h=10, Shrz=1
(Large A => stiff axially, Shrz=0 to negl shear defl)
>Material Properties
(enter or select from library)
>Material Library
(Don’t forget to select units!!!)
Select units <OK>
(English=BFT or BIN, feet or inches)
Select material from list
(N/A - the material library is not installed)
or
>Material Model >Structural >Linear >Elastic >Isotropic (double click)
Ex is Young's Modulus
30e6
PRxy is Poisson's Ratio
0.3
<Close window>
>Modeling>Create
(Create nodes)
>Nodes > In Active CS
(enter x, y, z coordinates from keyboard)
<Apply> to enter data and continue or <OK> to end
or
>Nodes > On Work Plane
(enter x, y, z coordinates using mouse)
>Modeling >Create
>Elements
>Element Attributes
(create beam elements)
(define each type of beam)
(select Type #, Material #, Real Constant #
or Shape for each change in beam properties)
Auto Numbered>Thru Nodes (choose 2 nodes for each beam, using mouse)
Pick 1-2 Apply, 2-3 Apply, 3-4 Apply <OK>
Model Check
Use the [List] and [Plot] options to check model geometry and coordinates
[List] >Nodes or [Plot] >Nodes
Coord. Only, by Node No. <OK>
[File] Copy to Output file [File> Close]
[List] >Elements (Nodes+Attrib+Const) or [Plot] >Elements
[File] Copy to Output file [File> Close]
Use [PlotCtrls] to change display
[PlotCtrls] >Numbering > Nodes
ON
Elements Colors and Numbers
[Plot] >Elements
(re-plot with colors)
Collapse the Preprocessor menu
[Save db]
(on ANSYS Toolbar)
(Back up your model before you execute solution!!)
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Loads, BC, and Solution
>Solution
>Analysis Type >New Analysis
(default is Static)
>Define Loads
>Apply >Structural
>Displacements - On nodes
(define constraints)
Pick node <Apply>
1
All DOF - as Constant <Apply>
4
X,Y dir - as Constant <OK>
>Apply >Structural
>Force/Moments - On nodes (define applied loads)
Pick node <Apply>
2 FX
-10000 <Apply>
(Check: Nodes All DOF
3 MZ
-20000 <OK>
Forces on all nodes)
NOTE: to apply a distributed load (called pressure load in ANSYS):
>Define Loads >Apply >Structural >Pressure >On Beams
Select: Beams<Apply>
Enter: Load number, I node pressure, leave J node blank
[Save db]
(Back up your model before you execute solution!!)
>Solve - Current LS (Load Step)
(submits completed problem to FEM solver)
Status window lists solution options executed. Banner appears: "Solution is done!"
Collapse the Solution menu.
[Save db]
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View Results
>General Postprocessor
>Plot Results
>Deformed Shape
Select: Deformed and Undeformed Shape <OK>
[PlotCtrls] Hard Copy
(see below)
>List input data: Nodal coordinates, elements, properties, real constants, loads, constraints.
>List Results: Nodal Solution,
DOF>Dispt Vector Sum
Reaction Solution
All Items
Element Solution
All Available Force Items
Element Solution >Line Element Results >Element Results <OK>
( Stress in local beam coordinates: X=beam axis, Y =max dist from neutral axis
SDIR=stress-axial, SBYT =stress-bending(Top), SBYB =stress-bending(Bottom) at I & J nodes
SMAX & SMIN are the sum of axial and bending stresses at each node)
(copy each list to the Output file)
>Print Results
[File] >Print
"lpr"
(default printer or –dctb 450 psa, -cb 230 ps2)
or...[File] >Copy to Output File
(send to file: jobname.out)
>Plot Element Solution
Graphic Screen Capture - Print or save to a file
[PlotCtrls] >Hard Copy
Select: Graphics Window, Gray Scale, Jpeg, Reverse Video, file name
Send to default printer: lp-d CB230ps
(substitute printer for your lab)
Or, Print to a File
(choose a file name)
NOTE! Reverse video is important! Black background uses too much toner.
Print Table or Output File
[File] >Print
(Use File option in the table window)
Send to default printer: lp-d CB230ps
(Substitute printer for your lab)
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Other ANSYS Features
Dependent Contraints
>Preprocessor
>Couple / ceqn
0 = -1*4Y + 0.2*4X
0 = -1*4X + 1*3X
0 = -1*4Y + 1*3Y
Angled constraint: at node 4, displ in Y dir. equals
0.2* displ in X dir. (i.e. positive slope)
Pin joint: coincident nodes 3 and 4 move together in the
X and Y dir, but rotate independently
Help
To print a Help file, use the [File] menu on the Help window.
Help - Table of Contents - Workbook
Sample Problems
Help - Table of Contents - Procedures Manual
Sec. 2.4 Typical ANSYS Analysis
Sec. 11.2 General Postprocessor
Sec. 12.5 Creating Graphs
App. A File Management
Help - Beam3
(description of beam elements)
Files Created by ANSYS
Look in your ANSYS directory.
jobname.db
Database file - your ANSYS input data
jobname.dbb
Backup of database file - created when you do a Save-db
jobname.emat
Element matrices
jobname.err
Error/warning log
jobname.esav
Saved element data
jobname.log
Command history - complete record of commands used in a session
jobname.out
ANSYS Output file
jobname.rst
ANSYS Results file
Accessing ANSYS from States
Login / Password
Create a subdirectory for ANSYS
Look at the directory
Move to the subdirectory
Rename files from previous runs
Execute ANSYS
UNIX commands
(Use the Xwindows interface if you prefer)
[ ] mkdir ansys
[ ] ls
[ ] cd ansys
[ ] mv fold.ext fnew.ext
[ ] xansys