Ansys Autodyn 121 Workshop 05

Workshop 5 Bird Strike

n ro uc on o AUTODYN

ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. Inc. All rights reserved. reserved.

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Release 12.1 February 2010

Workshop 5. Bird Strike

Workshop Goal and Procedure

Training Manual

Goal: Model a bird strike on

Procedure: Explicit Dynamics (ANSYS) AUTODYN Convert the Bird Part to use no es Run the analysis in AUTODYN

ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. Inc. All rights reserved. reserved.

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Step 1 – Start Workbench

Training Manual

Start ANSYS Workbench and follow the sequenced steps using the abbreviations shown below: – DC

= Double Click with Left Mouse Button

– SC

= Single Click with Left Mouse Button

– RMB = Right Mouse Button Selection – D&D = Drag and Drop = Hold Left Mouse Button down on item while dragging it to new location and then release it (i.e., Copy or Move)

Throughout these Workshops, the procedures shown are not always the only way to accomplish the desired tasks, so feel free to investigate other methods via the documentation when outside of this course • The workshops consistently use RMB in the Outline tree to access options whenever possible • Often these options can also be accessed through the “Context” Toolbar • Sometimes these options can also be accessed using RMB in the View area ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 2 – Initiate an Explicit Dynamics (ANSYS) Project

Training Manual

2.a Create an Explicit Dynamics (ANSYS) Project SC

DC

2.b Select MKS for the Project Units and request Native Applications in Workbench have their values Displayed in the Project Units ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 3 – Define Engineering Data Material .a

DC

Training Manual

e ng neer ng a a ce o se ec pre-defined material models from one of the pre-defined material libraries

3.b Select the Explicit Materials library. Materials in this library have physical proper y a a e ne or exp c ana yses

SC

ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 3 – Define Engineering Data Material ...

Training Manual

3.c Select the “+” sign to the right of AL5083H116 to add it to the Engineering Data library.

3.d Likewise, select the “+” sign to the right of WATER2 . Note the symbol of a book that appears indicating success


SC

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Step 3 – Define Engineering Data Material ... 3.e Go to the Engineering Data cell and note the

Training Manual

SC

3.f Return to the Project

3.g Save the Project by “ ” icon and Browse to the directory indicated by . “bird_strike” for the Project name


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Step 3 – Define Engineering Data Material ...

Training Manual

3.h Temporary fix

enter “0” for the Shear Modulus for WATER2. This is an error that will be fixed in the next release)

0


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Step 4 – Import the Geometry

Training Manual

4.a Import the geometry database bird_strike.agdb as shown below

RMB


SC

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Step 5 – Edit the Model in Mechanical

Training Manual

5.a Edit the model in Workbench Mechanical.

5.b Select the MKS Units system –

,

so the Units here may not match the Project Units


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Step 5 – Edit the Model in Mechanical ...

Training Manual

5.c Assign a thickness of “0.005” meters and the material AL5083H116 to Stiffener_1, Stiffener_2, Stiffener_3 and Stiffener_4 5.d Assign a thickness of “0.003” meters and the material AL5083H116 to Skin 5.e Assign the material WATER2 to Bird


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Step 5 – Edit the Model in Mechanical ...

Training Manual

5.f Notice the automatically defined Body Interaction. This allows a frictionless sliding interaction between all bodies


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Step 6 – Generate the Default Mesh

Training Manual

6.a Generate the default mesh

used to create a region of SPH nodes in AUTODYN

RMB

Default mesh is reasonable,


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Step 7 – Change the Mesh Method

Training Manual

RMB

SC

7.a Insert a Meshing Method 7.b Select all bodies

+ SC

(RMB in the view area) 7.c Deselect the Bird body ( + SC 7.d Select Apply ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 7 – Change the Mesh Method …

Training Manual

7.e Select Uniform Quad for the Method .

“ . ” Element Size

7.g Enter “0.025” m for the Defeaturing Tolerance 7.h Generate the mesh

RMB SC

The mesh is now uniform ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 8 – Define the Initial Conditions

Training Manual

8.a Apply an Initial Velocity Condition to the Bird as shown. Note: RMB

SC

Bird body


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If the Body selection filter is not automatically activated for the initial velocity condition, select it manua y.



Step 8 – Define the Initial Conditions ...

Training Manual

8.b Choose Define by Components: X = 250.0 m/s


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Step 9 – Define the Analysis Settings

Training Manual

9.a Select Analysis Settings in the tree

SC

9.b Set the End Time to 5.0e-3 seconds in the Details View 9.c Keep the remaining default settings

9.d Save the model on the Workbench At this point the project has been set up a much as is possible in Explicit Dynamics (ANSYS). It will now e rans erre n o o comp e e e setup for the SPH solver and run the analysis ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 10 – Create (Link to) an AUTODYN Project

Training Manual

10.a On the Workbench Project page, under Component Systems, AUTODYN component onto the Setup cell for the Explicit Dynamics (ANSYS) project. This creates an AUTODYN project ’ to the Explicit Dynamics Project

D&D

RMB

SC

10.b Open the AUTODYN project, importing the model se up n e xp c Dynamics project ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 11 – Load a Plot Settings File

Training Manual

11.a Load the plot settings file “bird_strike_1.set” to obtain the following view


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Step 12 – Generate an SPH Part for the Bird

Training Manual

12.c Enter “Bird_SPH” for the Part Name 12.d Select the SPH Solver

.a e ec Parts On Navigation

12.e Accept the data

12.b Select ew n e dialog panel ANSYS, Inc. Proprietary © 2010 ANSYS, Inc. All rights reserved.

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Step 13 – Create an SPH Object from the Bird Part

Training Manual

13.a Select Geometry (Zoning) 13.b Under Import Objects, select Part 13.c Select the Bird Part to convert to an object 13.d Name the Object “SPH_Bird” 13.e Accept the data


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Step 14 – Delete the (Lagrange) Bird Part

Training Manual

Now that the new SPH object has been created, the Bird Part (created in Explicit Dynamics) is no longer needed, so delete it 14.a Select Delete 14.b Select the Bird Part 14.c Accept the data New SPH Object


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Step 15 – Pack SPH_Bird Object with SPH Nodes

Training Manual

.e e ec n a Condition Set 3

15.g Enter 15.0 mm for the Particle (Water and 250 m/s) Size 15.d Check Fill 15.h Acce t the data 15.f Select next Condition Set

15.a Select ac 15.b Select the SPH_Bird object 15.c Select Pack Selected Ob ect s


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Step 16 – Load a Plot Settings File

Training Manual

16.a Load the plot settings file “bird_strike_2.set” to obtain the following view


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Step 17 – Set up the Bird / Wing Interaction

Training Manual

17.a Select Interaction on the Navigation Bar 17.b Select External Gap (this must be used for Lagrange/SPH interactions) 17.c Enter a Gap size of “1.5” mm 17.d Select Check A message will tell you that the input parameters are OK


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Step 18 – Run the Analysis

Training Manual

The calculation takes approximately 40 minutes to run to completion (about 7500 cycles)

18.a Save the project on the Workbench Pro ect Pa e 18.b Select Run to start

18.c Once the calculation is Select Stop at any time to stop the calculation you can en press Run again to continue the


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Ansys Autodyn 121 Workshop 05

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