ansys autodyn 120 workshop 06

WS 6-1ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved.

February 27, 2009Inventory #002665

Workshop 6

Bird Strike

ANSYS AUTODYN

Workshop 6. Bird Strike



Training ManualWorkshop Goal and Procedure

Goal:

Model a bird strike on an aircraft wing

Procedure:

Set up the problem in Explicit Dynamics (ANSYS)

Transfer the setup to AUTODYN

Convert the Bird Part to use SPH nodes

Run the analysis in AUTODYN




Training ManualStep 1 – Start Workbench

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




Training Manual

2.a Create an Explicit Dynamics (ANSYS) Project

2.b Select MKS for the Project Units and request Native Applications in Workbench have their values Displayed in the Project Units

Step 2 – Initiate an Explicit Dynamics (ANSYS) Project

DC

SC




Training ManualStep 3 – Define Engineering Data Material

3.a Edit the Engineering Data cell to select 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 property data defined for explicit analyses

DC

SC




Training ManualStep 3 – Define Engineering Data Material ...

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

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

SC





3.f Return to the Project Schematic

3.g Save the Project by selecting the “Save As”icon and Browse to the directory indicated by your instructor. Enter “bird_strike” for the Project name

SC

3.e Go to the Engineering Datacell and note the added materials





3.h Temporary fix

Return to Engineering Data and enter “0” for the Shear Modulus for WATER2.(This is an error that will be fixed in the next release)

0




Training ManualStep 4 – Import the Geometry4.a Import the geometry database bird_strike.agdb as shown below

RMB SC




Training ManualStep 5 – Edit the Model in Mechanical

5.a Edit the model in Workbench Mechanical.

RMB SC

5.b Select the MKS Units system– Recall that Mechanical is not native in Workbench,

so the Units here may not match the Project Units




Training ManualStep 5 – Edit the Model in Mechanical ...5.c Assign a thickness of “0.005”

meters and the material AL5083H116 to Stiffener_1,Stiffener_2, Stiffener_3 andStiffener_4

5.d Assign a thickness of “0.003”meters and the material AL5083H116 to Skin

5.e Assign the material WATER2 to Bird




Training ManualStep 5 – Edit the Model in Mechanical ...

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




Training ManualStep 6 – Generate the Default Mesh

6.a Generate the default mesh

Default mesh is reasonable, but not uniform

Quality of the Bird mesh is not important as it will only be used to create a region of SPH nodes in AUTODYN

RMB




Training ManualStep 7 – Change the Mesh Method

7.a Insert a MeshingMethod

7.b Select all bodies (RMB in the view

area)

7.c Deselect the Bird body (<control> + SC on body)

7.d Select Apply

RMB

<control> + SC

SC

RMB SC




Training ManualStep 7 – Change the Mesh Method …

7.e Select Uniform Quad for the Method

7.f Enter “0.025” m for the Element Size

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

7.h Generate the mesh

The mesh is now uniform

SCRMB




Training ManualStep 8 – Define the Initial Conditions

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

RMB SC

Note:If the Body selection filter is not automatically activated for the initial velocity condition, select it manually.

SC

Select the Bird body




Training ManualStep 8 – Define the Initial Conditions ...

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




Training ManualStep 9 – Define the Analysis Settings

9.a Select Analysis Settings in the tree

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 Project page

SC

At this point the project has been set up a much as is possible in Explicit Dynamics (ANSYS). It will

now be transferred into AUTODYN to complete the setup for the SPH solver and run the analysis




Training ManualStep 10 – Create (Link to) an AUTODYN Project10.a On the Workbench

Project page, under Component Systems, drag and drop the AUTODYN component onto the Setup cell for the Explicit Dynamics (ANSYS) project.This creates an AUTODYN project who’s setup is linked to the Explicit Dynamics Project

10.b Open the AUTODYN project, importing the model set up in the Explicit Dynamics project

RMB

SC

D&D




Training ManualStep 11 – Generate an SPH Part for the Bird

11.c Enter “Bird_SPH” for the Part Name

11.d Select the SPH Solver

11.e Accept the data

11.a Select Parts On Navigation Bar

11.b Select New in the dialog panel




Training ManualStep 12 – Create an SPH Object from the Bird Part

12.a Select Geometry (Zoning)

12.b Under Import Objects, select Part

12.c Select the Bird Part to convert to an object

12.d Name the Object “SPH_Bird”

12.e Accept the data




Training ManualStep 13 – Delete the (Lagrange) Bird PartNow that the new SPH object has been created, the Bird Part (created in Explicit Dynamics) is no longer needed, so delete it

13.a Select Delete

13.b Select the Bird Part

13.c Accept the data

New SPH Object




Training ManualStep 14 – Pack SPH_Bird Object with SPH Nodes

14.a Select Pack (Fill)

14.b Select the SPH_Bird

object

14.c Select Pack Selected Object(s)

14.d Check Fill with Initial Condition Set

14.e Select Initial Condition Set 3

(Water and 250 m/s)

14.h Accept the data14.f Select next

14.g Enter 15.0 mm for the Particle Size




Training ManualStep 15 – Load a Plot Settings File15.a Load the plot settings file “bird_strike_2.set” to obtain the following

view




Training ManualStep 16 – Set up the Bird / Wing Interaction16.a Select Interaction on the

Navigation Bar

16.b Select External Gap (this must be used for Lagrange/SPH interactions)

16.c Enter a Gap size of “1.5” mm

16.d Select Check

A message will tell you that the input parameters are OK




Training ManualStep 17 – Run the Analysis

17.a Save the project on the Workbench Project Page

17.b Select Run to start the solve

17.c Once the calculation is running, Select Stop at any time to stop the calculation (you can then press Runagain to continue the calculation)

The calculation takes approximately 40 minutes to run

to completion (about 7500 cycles)

ansys autodyn 120 workshop 06

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