FRANC3D Training Workshop: Part · PDF fileFRANC3D Training Workshop: Part III Drs. Bruce Carter, Paul “Wash” Wawrzynek, Tony Ingraffea, and Omar Ibrahim February - 2016 ... ANSYS

FRANC3D Training Workshop:

Part III

Drs. Bruce Carter, Paul “Wash”

Wawrzynek, Tony Ingraffea, and

Omar Ibrahim

February - 2016

Fracture Analysis Consultants, Inc.

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• General introduction to FRANC3D:

- capabilities and limitations

• Present theories and approaches to computational

fracture mechanics built into software

• Hands-on sessions give participants time to use

software

• Opportunity for participants to ask questions

Objectives

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Workshop Agenda

• Part I: Introduction to Fracture Mechanics Analysis

• Part II: Introduction to FRANC3D

• Part III: FRANC3D FE model import - demo & hands-on

• Part IV: Crack Insertion Process – demo & hands-on

• Part V: Crack Growth and Fatigue Life – Theory, Rules & Models

• Part VI: FRANC3D crack growth, SIF history & fatigue life

- demo & hands-on

• Part VII: FRANC3D Session Log, Playback, Command Line & Python

• Part VIII: Known issues & what to do if something goes wrong

• Part IX: Capabilities coming soon

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FE Model Import

Part III

FRANC3D FE Model Import

• FRANC3D support the following input

finite element files:

– ANSYS: *.cdb files

– ABAQUS: *.inp files

– NASTRAN: *.bdf(or *.nas) files

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FRANC3D has three options for importing uncracked FE Models

• Import a complete model

• Import and divide the model in FRANC3D

• Import an already divided model

Depending on selection, different dialogs will be displayed next.

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• After importing the finite element into FRANC3D, Select Retained BC

Surfaces dialog is displayed

• Any surface that has boundary conditions will be highlighted in blue

• Using the Select All button, the blue surfaces will be colored red

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Importing full model

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NOTE: do not retain facets where a crack will be inserted.

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Import and Divide the Model in FRANC3D

• After importing the full

FE Model, the Define a

Local Submodel dialog

box will appear

• FRANC3D supports

several options for

extracting the sub-model

• After extracting the sub-

model, the Select

Retained BC Surfaces

dialog if the sub-model has

boundary conditions or

node sets or surfaces

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• Cropping Options

– Allow one to specify which ‘side’ of the

selection plane or box is selected

– selected elements are colored red

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• Relative to a principal plane:

– Allows one to choose a plane that is aligned

with the Cartesian axe

– Plane can be offset from the origin

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• Plane normal and offset

– Allows one to define a plane that is normal to the

unit vector defined by the x, y and z coordinates

– Plane can be offset from the origin

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• Plane from three points

– Allow one to define a plane based on the selection of

three points

– Use the (cross) cursor to pick the point; three points of

a triangle define the plane

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• Rubberband box

– Allows one to define a box using the left-mouse

button to drag the outline of a box on the screen

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• Element by element

– Allows one to select (or unselect) individual elements

– User presses the Select button and then uses the left-

mouse button to select elements one at a time

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• By material

– Allows one to select elements based on the

material id

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• By element group

– Allows one to select elements based on an

element group name

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• Retained from file

– Allows one to select element id’s from a .txt file

– Useful for re-selecting elements that were selected during

a previous import

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• Crop, Undo and Redo – The three buttons at the bottom on the left side perform the actual

cropping operation

– Once the selection has been made using one of the options discussed,

the selected elements are cropped by pressing the Crop button

– Un-selected elements are removed.

– User can Undo or Redo the cropping operation

– Multiple selections and crops can be performed in sequence

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Import Already Divided Model

• If the user has divided the entire FE model

into global and local model (portion that

will cracked) files

• Files can be imported into FRANC3D

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Export Model • File Export menu item can be used to save the FE model data

without saving the FRANC3D .fdb

• User selects the analysis FE model type and enters the file name

• Used to convert FE model files from one type to another

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Reading Analysis Results

• File Read Results menu item allows the user to choose the

analysis results file to be read

• For ANSYS, FRANC3D reads

– *.dtp file (contains displacements, temperatures ) that is created using the

FRANC3D & macros

– *.dsp file (contains nodal listing of displacements).

• For ABAQUS, FRANC3D reads

– *.dtp file (contains displacements, temperatures ) that is created using the

FRANC3D & Python script

– *.fil file (contains nodal listing of displacements).

– ABAQUS CAE Report file format.

• For NASTRAN, FRANC3D reads

– *.pch file (contains displacements, temperatures )

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Reading Analysis Results

• Read results file dialog

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Demo: FE Model Import

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FRANC3D Tutorial 1

ANSYS ABAQUS NASTRAN

• 10x10x10 cube; units of length are mm

• subdivide edges for meshing using 10 to 20 subdivisions

• use quadratic brick or tetrahedral elements

• material properties: E=10000 MPa and n=0.3

• uniform traction (a negative pressure) on the top surface of 10 MPa

• bottom surface constrained in the y-direction, bottom left edge is also constrained in the

x-direction, and the point at the origin is also constrained in the z-direction

FRANC3D Tutorial 1

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FRANC3D Tutorial 1

Step 1: Build the FE model or use pre-made model

Step 2: Extract local sub-model portion from full model – create node component/set for cut-surface(s)

– write local and global portions as separate model files

– ensure local and global FE data self-consistent (does not contain extraneous data)

Step 3: Import sub-model portion into FRANC3D

Local and

global

defined in

FE code

Local and

global

defined in

FRANC3D

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FRANC3D Tutorial 1 – Import FE Model

For Step 2 when using FRANC3D:

Import and divide

full ANSYS model

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Submodel Tool:

• elements shown in dark grey are

retained when the model is Cropped

• Rubberband Box tool demonstrated


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Submodel Tool:

• Local and global portions saved along with list of retained

elements; the latter allows for scripted restarts (e.g., reanalysis).

Note that there are no

boundary conditions on

local model.

Cut-surface mesh facets retained

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Importing full model into FRANC3D:

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Surface mesh facets are retained where boundary conditions applied and

selected. If a crack is to be inserted into a surface that has boundary conditions,

do not select that surface to be retained.

Surface with boundary conditions has

mesh facets retained

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FRANC3D Tutorial 1 – before you start

Saved

camera

positions

provide

easy way

to show

different

views.

Default view control:

Left mouse button – rotate

Center mouse button – pan

Right mouse button – zoom and spin

Center mouse button + SHIFT key:

front clipping plane

Right mouse button + SHIFT key:

back clipping plane

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Allows user to cut away a portion

of the model based on cutting

planes aligned with the global

Cartesian axes.

Controls the speed of rotation, translation and zooming

when “moving” the model with the mouse.

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Clipping

Recenter

Visual display of

front and back

clipping planes.

Default center

of rotation is

the center of

the model.

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Set preferences for the FE analysis code,

such as location of executable, etc.

Select Accept to save settings – best to restart after.

Settings are saved to text file in users’ home folder: foxrc/FAC/Franc3D.ini

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Hands On: Import FE Model

Part III

Documents

FRANC3D Training Workshop: Part · PDF fileFRANC3D Training Workshop: Part III Drs. Bruce Carter, Paul “Wash” Wawrzynek, Tony Ingraffea, and Omar Ibrahim February - 2016 ... ANSYS