Using Finite Elements- Abaqus Mark Johnson

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

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

ABAQUS/CAE

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

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

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

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

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

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?

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

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

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

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 http://www.dynasupport.com/support-1/how-tos/consistent-units Using Finite Elements- Abaqus

How to set up a simple Abaqus analysis

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

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

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

(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

(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

(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

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

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

(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

(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

(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

How to set up an Image Based Model for analysis

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

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

(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

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

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

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

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

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

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

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

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

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