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ENGI 7706/7934: Finite Element Analysis
Abaqus CAE Tutorial 1: 2D Plane Truss
Lab TA: Xiaotong Huo EN 3029B xh0381@mun.ca
Download link for Abaqus student edition:
http://academy.3ds.com/software/simulia/abaqus-student-edition/
Problem Statement:
Consider the simple six-bar pin-jointed structure shown. All members have the same cross-sectional area (A = 0.001 m2) and elastic modulus (E = 200 GPa). The load P of 20 kN acts at an angle of 30 degrees from the vertical. The structure dimensions are in meters. Use ABAQUS to solve for the nodal displacements, element stresses and reaction forces.
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1.2.2 ABAQUS CAE Procedure – Preliminary Steps
Create Working Directory Create Working Directory
Open Abaqus CAE
Set Work Directory
File > Set Work Directory
Select Directory Created in step 1.1.
1.2.3 Create Part (Module: Part)
Click Create Part Icon
Name Part “Truss”
Select:
2D Planar Deformable Wire
Set Approximate Size to 50.
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Click Create Isolated Points
Enter the following coordinates (appearing in bottom left corner of drawing window)
Node X Y
1. 0 0 (Press Enter) 2. 4 0 (Press Enter) 3. 0 3 (Press Enter) 4. 4 3 (Press Enter) 5. 2 2 (Press Enter)
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Click Create Lines icon
Join Node 1 with 2 , Node 2 with 5, Node 5 with 4, Node 4 with 2 (now right click and cancel procedure)
Again, click create lines icon and join Node 3 with 5, and 5 with 1 (right click and cancel procedure)
Click on “Auto Fit View” appearing on window top, click “Done” appearing in window bottom
1.2.4 Material and Geometric or Section Properties (Module: Property)
Select Property from the Module Drop-Down Menu
Click Create Material Icon
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Enter Material Name “Elastic”
Select Mechanical > Elasticity > Elastic
Enter Young’s Modulus = 200e9, Poisson’s Ratio = 0.3
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Click Create Section Icon
Name Section “Truss”
Select Category “Beam”
Select Type “Truss”… Continue
Select Material “Elastic”
Set Cross-sectional Area = 0.001… OK
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Click Assign Section Icon
Select the Truss by holding left mouse key and selecting the entire truss…
Done
Select Section Truss… OK...Done
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1.2.5 Instance, Part and Model Generation (Module: Assembly)
Select Assembly from the Module Drop-Down Menu
Click Instance Part Icon
Accept Defaults… OK
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1.2.6 Define Load Step Conditions (Module: Step)
Select Step from the Module Drop-Down Menu
Click Create Step Icon
Name Step “ApplyForce”
Accept Defaults (Procedure Type: General > Static, General)… Continue
Enter Description “Apply Force to Truss Element at an Angle”
Accept Defaults on “Basic” Tab
Select “Incrementation” Tab
Enter Increment Size: Initial = 0.1… OK
1.2.7 Apply Essential and Natural Boundary Conditions (Module: Load)
Select Load from the Module Drop-Down Menu
Click Create Load Icon
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Name Load “CLOAD”
Select Category: Mechanical > Type Concentrated Force
Select Node 2 (x = 4, y = 0) … Done
Enter CF1 = 10000 (10.0 kN)
Enter CF2 = 17320 (17.3 kN)… OK
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Click Create Boundary Condition Icon
Name BC “Fixed”
Select Step: ApplyForce
Select Category: Mechanical > Type: Displacement/Rotation… Continue
Select Node 1 (x = 0, y = 0)… Done
Select Boxes to Left of U1, U2 and UR3
Accept Defaults (U1=U2=UR3=0)… OK
6.3.7. Repeat the procedure from 6.3 to 6.3.6 for Node 3 ( x = 0, y = 3) and Node 4 ( x =4, y = 3) [ Name boundary conditions to fixed 2 and fixed 3 respectively for these 2 nodes]
1.2.8 Mesh Generation (Module: Mesh)
Select Mesh from the Module Drop-Down Menu
Select Part: Truss (to Right of Module Drop Down)
Click Seed Part Instance Icon
Enter Approximate Global Size = 4 (As maximum truss length is 4 (truss1), and we will begin with one element)… OK… Done (bottom)
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Click Assign Element Type Icon
Select the entire truss by holding down left mouse key and selecting all 6 elements. Click Done. From the Default Element Library: Standard and Geometric Order: Linear, Select Family: Truss… OK…Done
Click Mesh Part Icon… Yes (Bottom)
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1.2.9 Field Output and Post-Processing Options (Module: Model Tree)
Edit Field output… Select required output data Expand Field Output Requests
Right-Click “F-Output-1”… Edit
Toggle On/Off Until Selected Output Variables are S (Stresses), E (Total Strains), UT (Translations), and RT (Reaction Forces)… Accept Other Defaults… OK
1.2.10 Submit ABAQUS Job (Module: Job)
Click Create Job Icon
Name Job “Truss”… Continue
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Accept Defaults… OK
Click Job Manager Icon
Click Submit
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Click Monitor to View Solution Progress
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1.2.11 Post-Processing and Data Analysis (Module: Visualization)
Dismiss Monitor
Click Results (enters Module: Visualization)
Click; Allow multiple plot states , Plot Undeformed shape, Plot Deformed shape, Plot Contours on Deformed shape
10.3. Click “Result” in the top menu, select “Options” and unselect
“Average element output at nodes”
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To make the visualization more prominent and to give element and node numbers, the following steps should be followed: Click on View in the top menu, select Graphics Options. In the Viewport Background Tab select
“Solid” and change color to “White” (click on blacktile to change background color). Click Apply, OK.
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10.6 For labelling Nodes and Elements Click on Options in the top menu, click Common, select `labels` tab, select ‘Show element labels’ and ‘Show node labels’ and set label colors to black. Hit Apply, OK.
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Click on Report in the top menu and select. “Field Output => Variable =>
Position: Unique Nodal => select U: Spatial Displacements => Apply =>
Unselect U
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After unselecting U, change “Position“ in the same pop up window to
“Centroid”. Select S: Stress Components => Click on ‘>’ and unselect all stresses except S11 => Apply.OK
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Open file ‘abaqus.rpt’ placed on the desktop and cut and paste desired results into MS Word
The following set of results will be generated; highlighting Nodal Displacements and Nodal Stresses
