ANSYS Workbench LS-DYNA Users Instructions

ANSYS Workbench LS-DYNAUsers Instructions

© 2013 ANSYS, Inc. ANSYS Workbench LS-DYNA Users Instructions 1

Release 14.5

March 15, 2013

Table of Contents

IntroductionInstallation Instructions Problem Setup• Engineering Data• Geometry• Body Interactions• Meshing• Initial Conditions• Boundary Conditions

Analysis SettingsResult Processing•


Result Processing• Stress• Strain• Global Data• Nodal Output• Body Data• Animation

LS-DYNA Keywords• Generated

Additional Information• Tips• Technical Support• License Requirements

Introduction

ANSYS Workbench LS-DYNA is a new user environment for running ANSYS LS-DYNA. It provides the extensive power of ANSYS Workbench environment to facilitate the use of the LS-DYNA program by greatly reducing the effort required to set-up and run complex problems.

Comprehensive CAD to solution capabilities include:• CAD import from all leading sources• Geometry clean-up to facilitate fast accurate explicit analysis• Parameters usable for optimization based on varying geometry,

material models and boundary conditions• State of the art meshing designed to produce high quality meshes

ideally suited for explicit simulations• Comprehensive post processing


In summary it is LS-DYNA empowered by ANSYS Workbench for ease of use and quick solutions unmatched by any other comprehensive pre and post processing environment offered in a single intuitive fully interactive, modern graphical user interface (GUI).

Workbench LS-DYNA is the result of a collaborative effort between Livermore Software Technology Corporation (LSTC) and ANSYS, Inc. The interface was created using the newly released ANSYS Customization Toolkit (ACT), a product of ANSYS, Inc. designed to enable customization of the user interface of ANSYS products. ACT was made available in Release 14.5.

Images courtesy of CADFEM GmBH

Introduction

The ANSYS LS-DYNA program is able to run the complete keyword set published in the LS-DYNA® KEYWORD USER'S MANUAL (Version 971 R6.0.0). In the current implementation, a limited subset of the extensive list of keyword inputs can be generated by Workbench LS-DYNA. The keywords generated through the standard user interface are supported by ANSYS technical support. The following areas of use are not supported with Workbench LS-DYNA:• User-defined material definition• LS-DYNA user subroutines• Mesh-free methods: SPH & EFG• Special elements such as Seat belt, Airbag, Draw-beads and others• Multi-material ALE• Fluid Structure Interaction (FSI)

Advanced, knowledgeable users may modify the input file generated


Advanced, knowledgeable users may modify the input file generated and take advantage of the full keyword set, however ANSYS, Inc. does not provide technical support for modified input files.

The Workbench LS-DYNA environment is available to all customers with an ANSYS LS-DYNA license and requires that license to run problems.

SMP Parallel processing is enabled. MPP will be available in the future.

These instructions assume that the users is familiar with the Mechanical GUI and the basics of LS-DYNA.

Workbench LS-DYNA is available from the Customer Portal Extension Library

Installation Instructions

If you have a previous version of

Workbench LS-DYNA follow the

instructions to uninstall it on P-7.

Administrator rights are required to

install Workbench LS-DYNA.

Download LSDYNA.zip from the

Customer Portal Extension Library

Unzip the file and double click on


Unzip the file and double click on

setup.exe (or double click on the zip file

and then on setup.exe

Click Run in Unknown Publisher warning

Click Next on Welcome page

Select “I agree” to accept license, then

follow instructions on the screen.

Start Workbench: Start/All

Programs/ANSYS 14.5/Workbench 14.5

Installation Instructions

Check to make sure that the Pre-load

the Mechanical editor option is checked.

This is the default, but has been

unchecked in the past by some users.


Once the installation is complete,

Workbench LS-DYNA will show up below

Design Exploration in the Toolbox and

you can start to set-up and run

problems. (see Problem Setup)

Un-Installation Instructions

In Workbench select:

Extensions/Manage Extensions, unselect

LSDYNA.


In Workbench select Tools/Options.

Click on Extensions and delete LSDYNA

form Default Extensions to Load. Exit

from Workbench

Un-Installation Instructions

In the Windows Control Panel select

Add/Remove programs

or Program Features

Select Workbench LSDYNA


Click on Uninstall

Problem Setup: Materials

These instructions will be most useful

for users who are familiar with the

Workbench ANSYS Mechanical user

interface as well as the use of the ANSYS

LS-DYNA program.

For background information or a

refresher, refer to:

Introduction to ANSYS Mechanical 14.5

and

Introduction to ANSYS LS-DYNA within


Introduction to ANSYS LS-DYNA within

Workbench 14.5

Problem setup is most efficiently done

when following the workflow offered by

Workbench LS-DYNA. Starting with the

project page:

Start with the Definition of Materials

Models from Engineering Data. Only the

material models supported by ANSYS LS-

DYNA are shown in Engineering Data for

Workbench LS-DYNA.

Problem Setup: Geometry

Select Geometry to be used, by creating

new geometry using DesignModeler or

SpaceClaim.

Alternatively import geometry from a

CAD model or a previously created

(.agdb) file.

Edit Model will start the Mechanical GUI


Edit Model will start the Mechanical GUI

Once the Mechanical GUI is open the

details of each part of the geometry can

be viewed

Problem Setup: Contact

Body Interaction parameters are

defined in the Connection branch of the

Model tree. Different types of contact

can be selected from the Contact

dropdown menu in the Connection

toolbar.

For the majority of problems Automatic

Contact can be used, requiring no

additional input by the user.


By default all bodies participate in

contact. The default contact is

frictionless, but can be changed.

Details of the contact are shown in the

Details of Body Interaction window.

Problem Setup: Springs

Springs can be added in Connections .

Both Longitudinal Stiffness and Damping

are supported.

Pre-loads are not supported.

Spring behavior can be Linear only.


Spring behavior can be Linear only.

Note for Release 14.5 Springs are a Beta

option, so the Workbench Beta flag

must be set.

Problem Setup: Meshing

Meshing is a critical part of explicit

simulations. Uniform size hexahedral

elements are ideal for accurate and fast

simulations. For complex geometries it

is difficult to generate an all hex mesh.

Workbench meshing continues to

improve the quality of the mesh

produced. As an example Mulitzone

meshing can automatically decompose

complex geometry into sweepeable


complex geometry into sweepeable

parts and create an all hex mesh.

Workbench LS-DYNA automatically

selects the explicit preference for

meshing, thus the mesher attempts to

produce a mesh well suited for ANSYS

LS-DYNA. The user need only specify an

element size to be used.

Problem Setup: IC

Initial Conditions can be assigned to

parts by inserting them in the ANSYS

LSDYNA branch or from the Supports

dropdown menu.


Problem Setup: BC

Boundary Conditions (Supports, Loads

and Acceleration) can be assigned to

parts by inserting them in the ANSYS LS-

DYNA branch or from the LS-DYNA

Environment dropdown menus.


Environment dropdown menus.

Specifications for Rigid Body and Rigid

wall constraints are available from the

Constraints dropdown menu

Problem Setup: Nodal Data

To collect Nodal Data, insert one or

more Result Trackers prior to running

the simulation. Result trackers must be

scoped to a node.

Add Nodal Output below the solution,

scope it to a node and select the type of

output.


Analysis Settings

Analysis settings control the running of

the simulation. The End Time is the only

required input.

SMP parallel processing can be activated


SMP parallel processing can be activated

by changing the Number of CPU’s. Note

that ANSYS LS-DYNA Parallel licenses are

required for more than 1 CPU.

Analysis Settings

Additional Analysis controls can be used

to select:

Single or double precision

Frequency of result outputs


Frequency of result outputs

Frequency of time history outputs

Note that by default Strain results are

not included in the output, and must be

selected by the user.

After the Analysis Settings are specified,

click on Solve to start ANSYS LS-DYNA.

Analysis Settings

Additional Controls

Using Section in the part definition,

additional controls of Element

Formulation and Hourglass Control are

also available to further specify how the

problem is to be run.


problem is to be run.

Result Processing

Once ANSYS LS-DYNA has been started,

Solution Information will display the

message file as the calculation runs.

Clicking on Stop Solution will terminate

the ANSYS LS-DYNA run.


Result Processing

Stress and Plastic Strain are

written by default (can be

suppressed) but Strain is not

written by default and must

be selected by the user if

desired.

Results can be inserted from

the Solution branch of the

tree.


Result Processing

Results can also be added from the

Solution toolbar


LS-DYNA keeps track of Total Strain and

Plastic Strain. Elastic Strain will always

show as 0. To plot plastic strain, use the

worksheet as shown on the next page.

Result Processing

LS-DYNA keeps track of Total Strain and

Plastic Strain. Elastic Strain will always

show as 0. To plot elastic plastic strain

or elastic strain, select User Defined

Results from the Worksheet.


Results: Nodal data

Time history plots at result trackers are

shown with Nodal Output. They can

show :


Results: Global Data

Time History Outputs (ASCII files) can be

requested. All the files listed below can

be created by ANSYS LS-DYNA from the

Workbench LS-DYNA GUI. Please note

however that some date in the ASCII


however that some date in the ASCII

files currently can not be viewed .


To view Time History Outputs select the ones desired from

the ASCII drop down menu.

Using LS-DYNA terminology, the following results can be

viewed within Workbench LS-DYNA:

• GLSTAT ( Global Data : Kinetic Energy, Hourglass, ....)

• BNDOUT ( Boundary Conditions Data )

• RCFORC ( Contact Forces Data)


• RCFORC ( Contact Forces Data)

• SPCFORC ( Reaction Forces on Boundary Conditions using *BOUNDARY_SPC ( Fixed Support)

To view Reaction Force

• MATSUM ( Body Data)

• NODOUT ( Nodal Data) Trackers must be defined during pre-processing for the nodal data to

be available during Results processing.


Define the time histories desired for

each plot In Details of Global Data click

on Tabular Data.

Expand the Datas pop-up box,

then click on the small table symbol,

then select from the dropdown box:

Multiple Items can be selected by


Multiple Items can be selected by

clicking on the data symbol for each:

To view the Global Data time history,

right click on Global Data under Solution

and select Generate. Then click on

Worksheet to view the results.



Results: Contact Force

Insert Contact Forces from the ASCII

dropdown list.

Select Body Interaction in Details of

“Contact Force”.

Right click on Contact Force and select

Generate.


Results: More ASCII Output

Similar to the Contact Force plot,

Material Output (Body data) and

Reaction Force plots can be added from

the ASCII Dropdown list and plotted.


Animations can be generated with one click


LS-DYNA Keywords

As noted in the Introduction, only the

keywords generated through the

standard Workbench LS-DYNA user

interface are supported by ANSYS

Technical Support.

This section describes the Keywords that

are generated and lists the Keywords

that are supported.

$# LS-DYNA Keyword file

*KEYWORD

*DATABASE_FORMAT

0 0

*CONTROL_TERMINATION

0.0007 10000000 0.001 1000 100000

*CONTROL_TIMESTEP

0 0.9 0 0 0 0 1 0

0 0 0

*CONTROL_CONTACT

0 0 1 1 1 0 2 0

0 0 0 0 0 0 0 0

0 0 0 0 0 0 0

2 1 0 1 0 1 0.5

0 0 0 0 0 0 0 0

1 0 0 0 1

*CONTROL_ENERGY

2 2 2 2


2 2 2 2

*CONTROL_ACCURACY

1 4 0

0

*CONTROL_BULK_VISCOSITY

1.5 0.06 -2

*CONTROL_SOLID

1 0 0 0

0 0 0 0 0 0 0 0 0 0

*CONTROL_SHELL

20 1 -1 4 2 1 1 1

0 0 0 0 0 1 1 0

0 0 2

*CONTROL_OUTPUT

1 0 0 0 0 0 0 0

0 0 0 0 0

*CONTROL_PARALLEL

0 0 1 0

*CONTROL_SOLUTION

0 0 0 0

LS-DYNA Keywords Generated - Materials


• Body Interactions

– Frictionless and Frictional creates

*CONTACT_AUTOMATIC_SINGLE_SURFACE

– Angular Velocity

– Both create keyword *INITIAL_VELOCITY.

• Manual Contact Regions

– Bonded creates *CONTACT_TIED keywords, either NODES_TO_SURFACE or

LS-DYNA Keywords Generated - Model


– Bonded creates *CONTACT_TIED keywords, either NODES_TO_SURFACE or

SURFACE_TO_SURFACE with the OFFSET option

– Bonded Breakable creates

*CONTACT_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK or

*CONTACT_ONEWAY_AUTOMATIC_SURFACE_TO_SURFACE_TIEBREAK

– Frictionless and Frictional creates *CONTACT_AUTOMATIC keywords, either

NODES_TO_SURFACE or SURFACE_TO_SURFACE

• Spot welds

– Breakable and Non-Breakable creates *CONSTRAINED_SPOTWELD

• Initial conditions

– Velocity

– Angular Velocity

– Both create keyword *INITIAL_VELOCITY.

• Loads

– Inertial: Acceleration and Standard Earth Gravity. Both create keyword

*LOAD_BODY_X, Y or Z depending on direction of acceleration.

– Pressure: creates *LOAD_SEGMENT_SET.

LS-DYNA Keywords Generated – Initial and Boundary Conditions


– Pressure: creates *LOAD_SEGMENT_SET.

– Force: creates *LOAD_NODE_SET.

• Supports

– Fixed Support: creates *BOUNDARY_SPC.

– Displacement: creates *BOUNDARY_PRESCRIBED_MOTION_SET.

– Velocity : creates *BOUNDARY_PRESCRIBED_MOTION_SET.

– Impedance Boundary: creates BOUNDARY_NON_REFLECTING.

– Simply Supported: creates *BOUNDARY_SPC.

– Fixed Rotation: creates *BOUNDARY_SPC.

Keywords: User Defined

Advanced users can take advantage of

the file include capability of LS-DYNA by

specifying the name of the file to be

included.

An include file *INCLUDE Filename1

keyword card will be generated pointing

to the file specified by the user.

Included files can contain any valid LS-

DYNA keyword cards created by the


DYNA keyword cards created by the

user. Using include files eliminates the

necessity of editing the .k input file by

the user each time the file is created by

Workbench LS-DYNA.

Note that included file can contain other

include file statements, providing a

fairly general capability for simply

adding predefined inputs.

ANSYS Support does not provide

technical assistance for keywords not

generated by Workbench LS-DYNA

The list of supported keyword is listed and explained in a

separate document:

ANSYS Workbench LS-DYNA Supported Keywords.pdf

LS-DYNA Keywords Supported


For an example of a quick step by step problem set-up,

please see the document:ANSYS Workbench LS-DYNA

Problem Set-up Examples.pdf which is part of the extension

package.

The LS_DYNA Keyword Manual, by default is located at:

C:\Program Files\ANSYS Inc\v145\ansys\docu

Additional Information: Documentation


C:\Program Files\ANSYS Inc\v145\ansys\docu

LS-DYNA_manual_Vol_I_R6.0.0.pdf

LS-DYNA_manual_Vol_II_R6.0.0.pdf

To be added translation from ANSY Mechanical to LS-

DYNA terminology

Additional Information: Terminology


In Release 14.5: 2D is not supported.

Do not modify the .k file within Workbench.

• As an alternative if possible use the “Input File

Include” option in the Constraints drop down menu.

• Alternatively, modify the .k file and launch LS-DYNA

with the Classic APDL Product Launcher and view the

Additional Information: Tips – Caution!


with the Classic APDL Product Launcher and view the

results with LS-Prepost.

• LS-DYNA cannot use pyramid elements. Check the

mesh statistics if you suspect that they may have

been generated by the mesher.

Workbench LS-Dyna with design points:

There is a know problem when using the option to export

each design point (by checking the Exported box in the table

of design points). This writes a new Workbench project for

each design point but the file log.html is deleted and the

Mechanical GUI cannot be opened. Possible error message:

Additional Information: Tips – Caution!


Mechanical GUI cannot be opened. Possible error message:

Work around:

Copy the original log.html file to each _dp project.

To cancel the Rigid Body Force

input via the “Tabular Data”

click “cancel” rather than the x

in the upper right corner.

Additional Information: Tips


To open Solver Files Directory

Generate .rst file




Once Workbench LS-DYNA has been installed, Workbench thinks

that you have made a change to the “project” even before doing

anything, so do not be surprise to see the message shown below

when trying to close Workbench or opening a project.


Commands snippets can be used:

• at the body level

– to modify the material, formulation

(section)

– hourglass and equation of state

– Note the section and hourglass can be

se directly through the GUI thus



se directly through the GUI thus

snippets may not be needed.

• at the contact level

– to use contact types not supported by

Workbench LS-DYNA

• At the environment level

– No command snippets are supported

and the environment liver. This

capability is partially replaced by the

input file include object

For technical assistance, please contact ANSYS Technical Support using any of the methods below:

Web: http://www1.ansys.com/customer/Phone: 800.711.7199 or 724.514.3600

Additional Information: Technical Support


Phone: 800.711.7199 or 724.514.3600Email: [email protected]

For existing technical support service requests, please reference the service request number when contacting ANSYS Technical Support.

"The ANSYS Workbench LS-DYNA User Interface is only available for use by licensees of ANSYS LS-DYNA, ANSYS LS-DYNA PC or ANSYS LS-DYNA PrepPost, who are current on maintenance or who have existing lease licenses of ANSYS LS-DYNA, ANSYS LS-DYNA PC or ANSYS LS-DYNA PrepPost. Such User Interface shall be treated as part of

Additional Information: Click-wrap license


PrepPost. Such User Interface shall be treated as part of the ANSYS LS-DYNA, ANSYS LS-DYNA PC or ANSYS LS-DYNA PrepPost program under the licensee's license agreement with ANSYS for the ANSYS LS-DYNA, ANSYS LS-DYNA PC or ANSYS LS-DYNA PrepPost program."

ANSYS Workbench LS-DYNA Users Instructions

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