Ansys Autodyn 120 Workshop 07

Workshop 7 Projectile Impacting Pre-stressed Container

ANSYS AUTODYN Update

ANSYS, Inc. Proprietary © 2009 ANSYS, ANSYS, Inc. All rights reserved.

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February 27, 2009 Inventory #002665

Workshop 7. Projectile Impacting Pre-stressed Container

Workshop Goal and Procedure

Training Manual

Goal: Model a projectile impacting a pre-stressed container

Procedure: Pre-stress a container in Static Structural (ANSYS) Link to Explicit Dynamics (ANSYS) and set up impact problem Transfer the setup to AUTODYN Run the pre-stressed analysis in AUTODYN ANSYS, Inc. Proprietary © 2009 ANSYS, ANSYS, Inc. All rights 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 © 2009 ANSYS, Inc. All rights reserved.

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Step 2 – Initiate a Static Structural (ANSYS) Project

Training Manual

2.a Create a Static Structural (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 © 2009 ANSYS, Inc. All rights reserved.

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Step 3 – Import the Geometry

Training Manual

3.a Import the geometry database pre-stress_impact.agdb as shown below

SC

RMB

ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.

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Step 4 – Edit the Model in Mechanical

Training Manual

4.a Edit the model in Workbench Mechanical

RMB

SC

4.b Select the MKS Units system – Recall that Mechanical is not native in Workbench, so the Units here may not match the Project Units


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Step 5 – Generate the Mesh

Training Manual

5.d Generate the mesh

RMB 5.a Select Mesh 5.b Select Explicit for the Physical Preference 5.c Enter an Element Size of “2.5e-3” meters ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.

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Step 6 – Define a Symmetry Plane

Training Manual

RMB

6.a Insert a Symmetry Object 6.b Insert a Symmetry Region 6.c Select the 11 faces shown and then select Apply 6.d Select Z Axis as the Symmetry Normal

RMB Select 11 faces


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Step 7 – Apply an Internal Pressure 7.a Insert a Pressure Boundary

Training Manual

RMB

7.b Select the 3 faces internal faces shown and then select Apply 7.c Enter 1.0e6 Pa for the Magnitude of the pressure


Select 3 faces

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Step 8 – Apply Fixed Supports to Container 8.a Insert a Fixed Support

Training Manual

RMB

8.b Select the 2 faces shown and then select Apply


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Step 9 – Apply a Fixed Support to the Projectile 9.a Insert a Fixed Support

Training Manual

RMB

9.b Select the face shown and then select Apply


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Step 10 – Define a Result Object 10.a Insert an Equivalent (vonMises) Stress Result object

Training Manual

RMB

10.b Apply the Geometry Selection to All bodies 10.c Save the Project from the Project Page with the name “prestress_impact”


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Step 11 – Solve to obtain Static Pre-stressing 11.a Solve the static problem

11.b View the prestressed solution

Training Manual

11.c Displacements are magnified by default. Change the magnification as desired

RMB

SC


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Step 12 – Link to Explicit Dynamics (ANSYS) 12.a From the Project Page drag and drop an Explicit Dynamics (ANSYS) Analysis System onto the Model cell of the Static Structural (ANSYS) System

Training Manual

D&D

\

12.b Notice that Engineering Data, Geometry and Model (Mesh) have been linked


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Step 13 – Review the Mechanical Project

Training Manual

13.a Return to ANSYS Mechanical and you will see that the project now has an Explicit Dynamics branch in addition to the Static Structural branch \

13.b Notice also, that a default Body Interaction has automatically been added to the project, defining Frictionless contact between All Bodies. This is exactly what is required to compute the impact of the projectile on the container


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Step 14 – Copy the BCs to Explicit Dynamics

Training Manual

14.a Select the Pressure and Fixed Support boundary conditions in the Static Structural branch (use ) and drag and drop them onto the Explicit Dynamics branch. (They are copied into the Explicit Dynamics branch) \

D&D 14.b Do not copy Fix Support 2 as this is not required for the Explicit Dynamics Solve (the next steps assigns a velocity to the projectile instead)


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Step 15 – Assign a Velocity to the Projectile

Training Manual

15.a Create a Velocity Initial Condition \

15.b Select the Projectile body and then select Apply 15.c Choose Define by Components 15.d Enter “-10.0” m/s for the Y Component ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.

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Step 16 – Define the Analysis Settings SC

Training Manual

16.a Select Analysis Settings in the tree 16.b Set the End Time to 4.0e-4 seconds in the Details View 16.c Set the Hourglass Damping to Flanagan Belytschko 16.d Keep the remaining default settings 16.e Save the model on the Workbench Project page

At this point, in order to apply the pre-stressing to the Dynamic analysis, the model must be transferred to AUTODYN for solution ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved.

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Step 17 – Create (Link to) an AUTODYN Project 17.a From the Project Page drag and drop an AUTODYN Component System onto the Setup cell of the Explicit Dynamics (ANSYS) System

Training Manual

D&D

\

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


RMB

SC

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Step 18 – Pre-stress the Container

Training Manual

18.a Select Init. Cond. On Navigation Bar 18.b Check Activate 18.c Browse to the results file “file.rst” for the static structural system (containing the pre-stress solution)


18.d Return to the Project Page and Save the Project

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Step 19 – Run the Pre-stressed Analysis 19.a Select Run to start the solve

Training Manual

The calculation takes approximately 10 minutes to run to completion (about 10,000 cycles)

19.b Once the calculation is running, Select Stop at any time to stop the calculation (you can then press Run again to continue the calculation)


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Ansys Autodyn 120 Workshop 07

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