1. Using Finite Elements- Abaqus
Mark Johnson

2. Using Finite Elements- Abaqus
Aims and objectives
Wednesday 09/06/10
Introduce Abaqus CAE
Layout
Modules
Model Tree
How to setup a simple Abaqus analysis
How to set up an Image Based Model for analysis
Thursday 10/06/10
Tutorials- hands-on session (students run their own analyses)
Using Finite Elements- Abaqus

3. Stepwise description of FEA
Preprocessing
CT scan
Thresholding
Segmenting
Model generation
Discretization
Mesh Generation
Material Properties
Boundary Conditions
Loading Conditions
ScanIP
ScanFE
Nodal displacements are used to calculate structural strain, and subsequently stress
FE Analysis
Abaqus (or ParaFEM + ParaFEM viewer)
Postprocessing
Representation and interpretation of FEA results
Using Finite Elements- Abaqus

4. ABAQUS/CAE

5. ABAQUS- Program Layout
Title Bar
Menu Bar
Tool Bar
Context Bar
Model /Results Tree
Viewport
Toolbox Area
Prompt Area
Message area or command line interface
Using Finite Elements- Abaqus

6. Using Finite Elements- Abaqus
ABAQUS- Modules
ABAQUS/CAE is divided into functional units called modules
Each module contains only those tools that are relevant to a specific portion of the modeling task
Order of the modules follows a logical sequence
A completed model contains everything that ABAQUS needs to start the analysis (e.g. boundary conditions, loading steps…)
Using Finite Elements- Abaqus

7. Using Finite Elements- Abaqus
ABAQUS- Modules
Part
Sketch and create parts.
Property
Define the material properties and other section properties.
Assembly
Assemble the model and create sets.
Step
Configure the analysis procedure and output requests.
Using Finite Elements- Abaqus

8. Using Finite Elements- Abaqus
ABAQUS- Modules
Load
Apply loads and boundary conditions.
Mesh
Meshing your parts.
Job
Create a job and submit it for analysis.
Visualization
View the results of the analysis.
Using Finite Elements- Abaqus

9. Using Finite Elements- Abaqus
ABAQUS- Model Tree
Organised format
At a glance overview
Hard to forget a step
Easy for someone else to follow
Using Finite Elements- Abaqus

10. Units I’m not confident in these results…
Has this structure deformed 2mm or 2km?
Units
What units are these results in?
Was the input force 50N or 50kN?

11. Using Finite Elements- Abaqus
Abaqus and units
Make sure you know what values and units you’re putting in, otherwise you won’t know what you’re getting out…
Using Finite Elements- Abaqus

12. Using Finite Elements- Abaqus
ABAQUS- Units
ABAQUS has no built-in system of units
All input data must be specified in consistent units
Using Finite Elements- Abaqus

13. Using Finite Elements- Abaqus
ABAQUS- Units
Mars Climate Orbiter
Pounds x newtons = crash
Using Finite Elements- Abaqus

14. Using Finite Elements- Abaqus
Be careful with units!!
MASS
LENGTH
TIME
FORCE 
STRESS
ENERGY
DENSITY
YOUNG's
35MPH    
56.33KMPH
GRAVITY
kg      m s N Pa J
7.83e+03
2.07e+11
15.65
9.806 cm
1.0e-02 N
7.83e-03
2.07e+09
1.56e+03
9.806e+02 ms
1.0e+04 N
2.07e+03
1.56
9.806e-04 us
1.0e+10 N
2.07e-03
1.56e-03
9.806e-10 mm KN
GPa
KN-mm
7.83e-06
2.07e+02
9.806e-03 g
dyne
dy/cm²
erg
7.83e+00
2.07e+12
1.0e+07 N
Mbar
1.0e+07 Ncm
2.07e+00
1.0e-06 N
1.56e+04
9.806e+03
MPa
N-mm
2.07e+05
ton
7.83e-09
lbfs2/in in
lbf
psi
lbf-in
7.33e-04
3.00e+07
6.16e+02
386
slug ft
psf
lbf-ft
1.52e+01
4.32e+09
51.33
32.17
kgfs2/mm
kgf
kgf/mm²
kgf-mm
8.02e-10
2.07e+04 kg mN
1.0e+03 Pa
2.07e+08
1.0e+05 Pa
2.07e+06
Using Finite Elements- Abaqus

15. How to set up a simple Abaqus analysis

16. Using Finite Elements- Abaqus
Overview of Tutorial 1.
Loading a cantilever beam
Using Finite Elements- Abaqus

17. (Tutorial 1.) Creating a part
Sketch in 2D
Extrude to make 3D beam
Using Finite Elements- Abaqus

18. (Tutorial 1.) Creating a material
Double-click Materials in the Model tree
Name the material
Assign material properties
Using Finite Elements- Abaqus

19. (Tutorial 1.) Configuring your analysis
To perform an analysis it is necessary to have at least two steps;
An initial step, in which you will apply boundary conditions that constrain the model
An analysis step, in which you will apply a load t0 the model
Using Finite Elements- Abaqus

20. (Tutorial 1.) Boundary Conditions
Apply in initial step
Boundary conditions are applied to those regions of the model where the displacements and/or rotations are known
Such regions may be constrained to remain fixed during the simulation or may have specified, nonzero displacements and/or rotations
Using Finite Elements- Abaqus

21. (Tutorial 1.) Loading Conditions
Apply in analysis step
In ABAQUS the term load generally refers to anything that induces a change in the response of a structure from its initial state, including:
• concentrated forces,
• pressures,
• nonzero boundary conditions,
• body loads, and
• temperature (with thermal expansion of the material defined)
Using Finite Elements- Abaqus

22. (Tutorial 1.) Meshing the model
Assign the element type
Seed-> Part
Mesh-> Part
Using Finite Elements- Abaqus

23. (Tutorial 1.) Creating an analysis job
Double click on ‘Jobs’ in Model Tree
Name the job
Using Finite Elements- Abaqus

24. (Tutorial 1.) Checking the model
Make sure that the Job Type is set to Data check
You should always perform a data check analysis before running a simulation to ensure that the model has been defined correctly and to check that there is enough disk space and memory available to complete the analysis
Make any necessary corrections to your model. When the data check analysis completes with no error messages, run the analysis itself
Using Finite Elements- Abaqus

25. (Tutorial 1.) Running the analysis
Change Job Type to ‘Full analysis’ by editing job
Right-click on Job in Model Tree→Submit
Using Finite Elements- Abaqus

26. (Tutorial 1.) Postprocessing the results
Switch to Results Tree
Can visualise;
Stress
Strain
Displacement etc
Again, this could be a lecture in itself!
Using Finite Elements- Abaqus

27. How to set up an Image Based Model for analysis

28. Using Finite Elements- Abaqus
Overview of Tutorial 2.
Loading a femur
300N
Using Finite Elements- Abaqus

29. (Tutorial 2.) Importing the model
Using Finite Elements- Abaqus

30. (Tutorial 2.) Differences to Tutorial 1
No need to create/sketch a part as it’s an image based model analysis
Material already created in Model Tree
No need to define and assign section properties -> automatically generated
Model has already been assembled
Femur model mesh generated in ScanFE
Using Finite Elements- Abaqus

31. (Tutorial 2.) Checking/Assigning Material Properties
Ebone= 20GPa
v= 0.3
Using Finite Elements- Abaqus

32. (Tutorial 2.) Creating analysis step
Accept defaults
Using Finite Elements- Abaqus

33. (Tutorial 2.) Assigning Boundary Conditions
Hold down Shift+ Left Click with mouse
Click done
-> Encastre
Using Finite Elements- Abaqus

34. (Tutorial 2.) Loading the femur
Check step
Surface traction
Traction= General
Enter force magnitude= 300N
Using Finite Elements- Abaqus

35. (Tutorial 2.) Running the analysis
Right-click on Job in Model Tree→Submit
Using Finite Elements- Abaqus

36. Using Finite Elements- Abaqus
(Tutorial 2.) Results
View results…
Using Finite Elements- Abaqus

37. Using Finite Elements- Abaqus
Further Tutorials
Abaqus
If you’d like this harder tutorial (3 hours) ask for the pdf.
Using Finite Elements- Abaqus

38. Using Finite Elements- Abaqus
FEA- Case study
Barn owl claw
Using Finite Elements- Abaqus

39. Using Finite Elements- Abaqus
FEA- Case study
Manning et al. (2009)
Velociraptor and Protoceratops (IGM 100/25).
Manning et al. (2009)
Manning et al. (2006)
Using Finite Elements- Abaqus