Catia assembly design.ppt

Copyright DASSAULT SYSTEMES 2002 1
Assembly Design
Fundamentals
CATIA Training
Foils
Version 5 Release 8
January 2002
EDU-CAT-E-ASM-FF-V5R8

Course Presentation
1 day
Targeted audience
New CATIA V5 Users
Objectives of the Course
In this course you will learn to create and manage CATProduct files
Prerequisites:
CATIA Part Design Fundamentals V5

Table of Contents
1. Introduction to Assembly Design p 4
2. Assembling Components p 12
3. Positioning Components Using Constraints p 42
4. Analyzing Assembly p 97
5. Editing Parts in an Assembly p 122
6. Working with Components p 139
7. Flexible Sub-Assemblies p 177

Introduction to Assembly Design
• Assembly Design QuickStart
• Assembly Design Workbench Presentation
You will become familiar with the main work on assemblies
such as inserting components and constraining them

Accessing the workbench
Exploring the User Interface
Terminology
Understanding the general process
You will learn about the Assembly Design Workbench by :
Assembly Design Workbench Presentation

Accessing the Assembly Design Workbench (1/2)
To access the Assembly Design Workbench,
Start CATIA, then select the Start menu choosing Mechanical Design and Assembly
Design.
The first time you access the Assembly Design Workbench if no window
is open , a new Product is created
Assembly Design
Workbench icon

Accessing the Assembly Design Workbench (2/2)
You can insert Assembly Design Workbench in a list of your favorite worbenches and
acces it by the Workbench and Worbenches Toolbars.
This Assembly Design Workbench can
be now acces at the Top of the Start
Menu
1 Select Tools / Customize and drop Assembly
Design on the Favorites List 2a
2b
Acces by Worbench Toolbar
Acces by Worbenches
Toolbar

User Interface: Assembly Design Toolbars
Constraint
Assembly tree
Components
Product
Structure
Move
Measure
Standard Toolbar
Compass
Catalog Browser
Weld Planner
Annotation
Annotations
Scenes
Filter Selection

Update
Snap
Manipulate
Explode
Coincidence Constraint
Contact Constraint
Offset Constraint
Angle Constraint
Fix Component
Fix Together
Quick Constraint
Flexible/Rigid Sub Assembly
Change Constraint
Reuse Pattern
Manage Representation
Fast Multi-Instanciation
New Component
New Product
Existing Component
Replace Component
Measure Between
Measure Item
New Part
Product structure Reordering
Generate Numbering
Product Init
Catalog
Browser
Measure Inertia
Weld
Planner
Flag Note with Leader
Text with Leader
User Interface: Assembly Design Icons

• A component is the general terminology . It can be a part or a assembly (inside an assembly it is
called a sub-assembly).
• An Assembly or Product is a collection of components and constraints them. Assembly
documents have the file extension CATProduct.
• Parts and assemblies have a Part Number (the Name of the component).
All instances of a part or assembly have the same Part Number. Each instance can have its own
Instance Name that identifies the instance.
• The active item is the item currently being edited. You make it active by double-clicking on it.
• Selected items are highlighted.
Instance name by default is in
parenthesis
Active item is in blue
Selected component
is highlighted
Component that
is a part
Component that is an
sub-assembly
Part Number
Terminology

General Process
Create a new assembly
or
open an existing one
Add, delete,
and replace
components
Position
components
using constraints
Analyze the
assembly
Capture various states of
the assembly for analyzing
the design and preparing
for drafting
Design parts in the
context of the
assembly

• Creating a New Assembly Document
• Adding Components
• Assigning Component Properties
• Saving an Assembly Document
Assembling Components
You will learn to create a new assembly, add components, assign
properties, and save documents

You will learn how to create a new Assembly Document
Creating a New Assembly Document

What is an Assembly Document ?
An Assembly Document is a document that is also called a Product because of its
file extension .CATProduct.
An Assembly or Product is a collection of components
blank sheet behind the component
icon means that the component is
linked with an external file
A assembly may contain a
another assembly,
It is called a sub-assembly
Full-clamp.CATProduct
In this example,
One file sub-clamp.CATProduct for 2 Instances
Clamp-pad.CATPart

Creating a New Assembly Document
Ways to create a new document:
1- Start menu
2- File menu
3- Workbench Icon
Assembly Design
Workbench icon

Product tab
1
2
3
Properties
Right-click the assembly
4
Key the Part Number and
other properties
Description information, called Product Properties, can be keyed for the
new Assembly Document.
Assigning Product Properties

You will learn how to add new and existing components to an assembly
Adding Components

What are Components ?
In it’s simplest form, a Component is a Part or Assembly that has been inserted into
an assembly. However, a Component can also be represented by data that is not
native to V5, such as V4 models, IGES, STEP, and VRML.
The root assembly
CATPart component
CATProduct component
V4 model component
Component that exists only
in the parent CATProduct
and does not have its own
file

Most visible way is to select the
assembly and use the icons in the
Product Structure Toolbar
2
1
Fastest way is to right-click the assembly
(that will receive the component) and use
the Contextual Menu to insert the
component
3
Last way is to select the assembly and
use the Insert Menu
There are three ways to insert components into an assembly: Contextual Menu,
Product Structure toolbar, and Insert Menu.
Adding Components

1
2
3b Double-click the file to insert
Existing Component
Often you will want to insert existing files as components. Inserted files are not
copied into the assembly, they are just “referenced” by the assembly.
You can import more than one component at
a time by selecting with the mouse while
holding the [SHIFT] or [CTRL] key
3a Choose a filter if desired (for example, CATPart, CATProduct,
model, etc)
Inserting an Existing Component

4
If you pressed YES, select a point or a component to
define the origin of the new part
Press YES to define an origin for the new part
that is different from the origin point of the
assembly, otherwise press NO
•If you select a component , the origin point of the
new part will be the same as the origin point of the
selected component
•If you select a point, the origin of the new part
will be exactly this point
New parts (CATParts) can be inserted on-the-fly while designing an assembly.
Key a Part Number for the new part. This
sets the Part Number property.
3
2 New Part
1
Inserting a New Part

Select “Product Structure”
tab
1 2 3
Select “Product
Structure”branch under
“Infrastructure” node
As a shortcut, Part Number properties can be keyed when inserting a new
part in an assembly.
4 Activate Manual input
Select Options... from
the Tools menu
Insert a New Part
User Setting: Turning ON Manual Input of Part Numbers

New assemblies (CATProducts) can be inserted on-the-fly. New Product Command will
create a new sub assembly in the selected component but also a new external
CATProduct file with the same name.
Key a Part Number for the new assembly. This
3
2 New Product
1
blank sheet behind the component
icon means that the component is
linked with an external file
Inserting a New Product

You can create a special type of component that exists only in the
parent CATProduct and does not have its own file.
Here are one component that exist in
the parent CATProduct and do not
have its own file.
You can insert in it components
Key a Part Number for the new assembly. This
3
2 New Component
1
There is no blank sheet behind the
component icon : there is no link with
an external file.
Inserting a New Component

It can be useful to insert in your assembly standard components that
are only available through Catalogs where they are referenced
This screw which
is referenced in a
catalog needs to
be inserted in
your assembly
Why Inserting a component from a catalog ?

In standard toolbar, select the Catalog Browser
2
3
1
Open chapters until you
get the end chapter in
which the element you
want is referenced
To insert the element inside your document you can either :
- drag and drop it in the destination product (A)
- make a copy with contextual menu of element and paste in
destination product of your document (B)
In the Assembly Design Workbench you can insert components from
catalog referencing CATPart files or CATProduct files
(B)
(A)
Inserting a component from a catalog

1
2
3
Right-click the
component to be copied
Copy
Right-click the assembly in which you
want to paste the component
After pasting there are two
instances of the part
Copy-and-Paste is an easy way to duplicate a component.
4 Paste
You can also use shortcuts
Another way to copy-and-paste a component
is to press [CTRL] while dragging the
component onto the assembly.
[CTRL] key
Instance name
Copy-and-Paste a Component

You will learn how to set component text properties
Assigning Component Properties

Component Properties can be assigned to distinguish
or describe an instance of a component.
Component Properties:
• Component Property values
can vary by component.
• These properties are stored
in the parent assembly’s
CATProduct file.
Product Properties:
• Product Property values are
the same for all instances of
the component.
• When the component is a
CATPart or CATProduct,
these properties are stored in
the CATPart or CATProduct.
• When the component is a V4
model, they are stored in the
in the parent assembly’s
CATProduct file.
Instance Name
What are Component Properties ?

1
Nodes Customization.
Instance
Name
Part Number
Select Tools / Options.
Select Product Structure and
Nodes Customization
2
3 Activate Customized Display and
select yours desired options
Assigning Component Properties (1/2)

Product tab
5
6 Properties
Right-click the component
4
Like other properties, component text properties can
be easily accessed from the contextual menu.
Component
Property
values can
vary by
component.
Product Property
values are the same
for all instances of a
part or assembly.
Key an Instance Name
and/or Description
Assigning Component Properties (2/2)

You will learn how to save an Assembly Document
Saving an Assembly Document

There are various ways to save an Assembly Document and
child documents.
Save will save the active component’s document and
child documents of the active document
Save As... is similar to Save, but it allows you to specify
the name and folder for the active document
Save All will save all the open documents that have been
modified since last save
Only those documents that have been modified will be saved or proposed to
save.
Save Management will propose saving all open documents
and children of these document, but you can control names
and locations of all of them
Saving an Assembly Document ...

Save As… allows a file name and folder to be specified. It allows you to create a
brand new document with new internal identifiers.
1 Activate the document to be saved
2 Save As...
4 Specify if you want to regenerate
internal identifiers
The active CATProduct document and any modified
child documents will be saved
Regenerating Internal
Identifiers will avoid
instantiation conflicts
with the reference
Specify a file name
and folder
3
Saving a Document under another Name

Save All is an easy way to save all modified documents
which are not new or read only documents.
1 Save All
2a If all the documents modified since last
save are not new (just created) or read
only files, you won’t have any message
and CATIA will save them
All modified open documents will be
saved, regardless of which document is
active
2b
If some of the documents modified since last save
are new (just created) or read only files you will
have this message
And clicking on OK will give
you access to the “Save All
As” command
3b
Saving all Modified Documents

This command is useful to save all the modified or linked documents under
selected names and directories
Modified Components
What is Save Management ?

This command is useful to save all the modified documents under other names and
directories
1
Make modifications on
components
In this case, editing the Axis.CATPart
file , we have increased the diameter of
pad1 from 10 to 13 mm and the
AxisNut.CATPart was impacted and
modified also. We do have 4 modified
documents
Save Management (1/5)

This command also remind you of what you have modified since last save.
2
Select “Save Management …” from
File menu
Number of unsaved modified files since
last load
If the file has been modified
or saved since last load, it is
indicated in the “State”
column
3 Select the file you
want to save
No “save as” will be performed
until you have clicked on OK
Names of all files
currently used are
displayed ...
… and their paths
as well .
4 Select “Save as...”

This command also remind you of what you have modified since last save.
Select the destination folder and name
of the new created file and select
“Save”
5
Destination
Folder
Name
“Save” is indicated for the selected
document, and “Save Auto” for its child
documents
6
Actions that will
be performed
when clicking Ok

If you click on OK as there are
still unsaved files left, CATIA
will display this message...
...and will save only the
documents that have a “Save”
or “Save Auto” Action
If you select for the “save as” a CAT product and if other modified documents are referenced by it ,
those ones will get “Save auto” in the Action column and will be saved when clicking Ok
Once you have saved a product in a new directory, you
have the possibility to save the files referenced by the
product into this directory just by clicking on the
“propagate directory” button.
This command automatically save impacted files too
To know what are documents called by a
CATProduct, use Links command from Edit
menu or Desk from File menu

You can change your mind about the way you save the document thanks to Reset button
and it is not mandatory to save a document under another name thanks to Save button.
You can get back the original state of the document by selecting it and
clicking on “Reset”
You can choose to keep same name and folder for a document and in this
case use the save button

• Freely Moving Components
• Creating Assembly Constraints
• Updating Assembly Constraints
• Creating Quick Constraints
• Multi Constraints Modes
• Hiding Constraints
• Filtering Constraints
You will become familiar with positioning components in an
assembly using assembly constraints
Positioning Components using Constraints

You will learn how to use the Compass to freely move
components which makes it easier to position components when
setting assembly constraints
Freely Moving Components

How the Compass can be Used ?
The Compass can be used to pan and rotate the entire session
or freely drag and rotate components in an assembly.
Panning and rotating the
entire session
Freely dragging and
rotating components
Here the entire session rotated
around the X-axis.
The rotation is temporary because
it is not stored in CATPart or
CATProduct documents.
Here a component is freely
rotated around the X-axis.
The rotation may be permanent
because it is stored in
CATProduct documents.
You will find it convenient to freely drag
and rotate component to make it easier to
create assembly constraints

1 Move your cursor over the little red
square of the compass to get this
cursor icon
2
3
When the component is selectable, the compass takes the
orientation of the geometric element that is under the
compass. To select, release MB1.
Positioning the Compass to Move a Component
The first step in freely moving a component is to position the
Compass on a component.
Press and hold down MB1 to drag the
compass. When moved, the compass
takes this shape.
If you release MB1 before any
component selection, the compass will
return to this point.
A component is selectable when this
point disappears
Green highlighted compass means that a
component is selected and that you can
move it
Once a component is selected , you can
select any other one by clicking on it, and
compass when moving will drag it.

1 Place the compass on a
component
2
Rotation around
an axis
Rotation around the
origin of the compass
Translation along
a plane
3 With MB1 held down,
move the component
Freely moving a Component using the Compass
Here are the basic steps for freely moving a component.
Select the type of movement by moving
the cursor on the Compass. The
highlighted compass elements indicate
the available movement.
Translation along
an axis
To move a component while respecting
the constraints, press [SHIFT] while
pressing MB1 and moving the
component.
[SHIFT] key

component
Translating a Component using the Compass
Here are the basic steps for translating a component using the Compass.
2 Right-click on the compass and
select Edit...
3a Specify translation distances by:
• Keying values; or
3b Move the component by:
4
Fix-Together the components if they will
not otherwise be constrained
• Selecting elements using the
Measure Distance… button
• Selecting one of these “-” and “+” buttons
to move along the U, V, and W directions
• Selecting one of these “-” and “+” buttons
to move along the U, V, and W directions

component
select Edit...
3a Specify a rotation angle by:
• Keying a value; or
3b Move the component by:
Rotating a Component using the Compass
Here are the basic steps for rotating a component using the Compass.
4
Fix-Together the components if they will
not otherwise be constrained
• Selecting elements using the
Measure Angle… button
• Selecting one these “-” and “+” buttons
to rotate around the U, V, or W axis

2 Select a component and the compass will “jump” to the
origin of the selected component
select Edit...
4a Specify a position by keying values 4b
Move the component by pressing the
Apply New Position button
Setting the Absolute Position of a Component
Here are the basic steps for setting the absolute position of a component.
1
Right-click on the compass and activate Snap
Automatically to Selected Object
The absolute position in the Compass Edit
window is actually the position of the compass,
not the position of the component.

You will learn how to Position components setting Assembly Constraints
Creating Assembly Constraints

What are Assembly Constraints ?
Assembly constraints provide an intuitive way to position components with
respect to each other. The process for creating constraints is described here.
1 Using the Compass, freely drag and rotate
components to make adding constraints easier
Fix-in-space one component in each
assembly that will serve as the base
2
3 Set the position of components by
specifying constraints
4 Update (regenerate) the constraints to move
the components into position

Setting Assembly Constraints ...
You have several ways to reach constraints icons and several ways to
use them
1 To set a constraint between two components, you can
either:
To reach the icons, you can either use: 2
the Constraint toolbar
or the Insert Menu
First click on the icon then select the Elements you
want to constraint
or first select or multi select the elements to
constraint and click on the icon
Note that in the second case you may have to use the [Ctrl]
key to multi select elements whereas in the first case, CATIA
will be waiting for a next selection

2 Select Assembly Design branch under
“Mechanical Design” node
You control whether or not CATIA automatically updates assembly
constraints (positioning of components) after making a change.
Manual Update for Assembly Design
Activate Manual
3
It is preferable to use Manual Update mode so that components do not move around
before being fully positioned (fully constrained).
1 Select Options... from the Tools menu

1
2 Select the component in the tree
or in geometry
3 The component is fixed in
space
Fix
Components that are Fixed in space return to their fixed-in-space
position when constraints are updated (regenerated).
Fixing a Component in Space (1/2)
It’s a good idea to fix-in-space one component
in each assembly that will serve as the base

CRIC_FRAME can’t move
After Update
Drag Cric Frame with
the Compass

1
2 Double-click the Fix constraint
3 Select the More>> button
Fix
Fixing a Component (1/2)
Fix is like Fix in Space, but when constraints are updated, it will only stay at its current
place and will not go back to a “fixed in space” position.
4
Deactivate the Fix in Space
option

After Update
Drag Cric Frame with
the Compass

Fixing-Together Components
Components that are Fixed-Together move as a single entity when
updating (regenerating) constraints.
1
2 Select the components to be Fixed-Together
Fix Together
As a matter of practice, it’s a good idea to Fix-Together
components that will not otherwise be constrained. This
will ensure that components are not unintentionally
moved out of position.

1
2
Select “Assembly Design”
branch under “Mechanical
Design” node
Fix-Together constraints are used to “glue” components together. Using the
Compass it is possible to unintentionally separate Fixed-Together components.
User Setting: Turning On Fix-Together Warning
We will activate the warning so that components belonging to a Fix
Together constraint are not accidentally moved out of position.
3 Activate
warning
the Tools menu
Use “General
tab”
4

You will be warned when attempting to move a component that is Fixed-Together.
The warning can be disregarded, but beware that the new position is permanent.
Disregarding the Fix-Together Warning
For example, when attempting to
Snap this component
1
You will see this warning
2
After pressing OK you can continue to
move the component
3
But beware that pressing Update will not move the
component back in position. It has a new position
within the Fix-Together
4
Immediately press Undo if you did not intend
to move the component.

Creating a Coincidence Constraint (1/2)
Coincidence creates alignment that can be coaxial, coplanar, or merged
points.
coaxial
coplanar
merged
points
1 Coincidence
2
Select the two elements to
specify the constraint
The constraint is created and the
elements are aligned

Creating a Coincidence Constraint (2/2)
Concerning coplanar alignment, CATIA gives a choice of orientation with two
green arrows
1
2
Just click one of those green
arrows to invert the orientation
of the moving component.
Select two planes as
geometric elements for
the constraint
When putting a constraint between
two components, the moving
component will be the first selected
if it is not fixed or fixed in space
1st
selection
2nd selection
3
Coincidence
4
Click on OK when the
orientation is correct

Creating a Contact Constraint
Contact mates two planes or faces.
1 Contact
2
The constraint is created and the
elements are mated
Notice that the Pre-selection
Navigator to select elements
that are hidden

3b
Key the offset
Creating an Offset Constraint
Defines an offset between two elements.
1 Offset
3a
Select the orientation
2
1st selection
Click on Ok when
you are satisfied
with specifications
By selecting an orientation in
the “Orientation” Combo box
4
By clicking on a green arrow
2nd selection

3b Key the angle
Creating an Angle Constraint (1/2)
Defines angle, parallelism and perpendicularity.
1 Angle
3a
2 Select the two elements to
The constraint is created and
the elements are offset
Select the type
4

4
Creating an Angle Constraint (2/2)
Concerning parallelism between two planes, CATIA gives a choice in the orientation of
the components.
1 Angle
3
2
Select two planes as
geometric elements to
Click OK when
satisfied with
specifications
Select the type
Select the
orientation
By selecting an orientation in
the “Orientation” Combo box
By clicking on a green arrow
5

Constraint Rules
There are a few simple rules that CATIA automatically enforces.
(1) This constraint cannot be applied because
Product K does not belong to the active
component Product B. To define this constraint,
Product A must be made active.
(2) This constraint cannot be applied because
Product E and Product F both belong to a
component other than the active component
Product B. To define this constraint, Product D
must be made active.
(3) This constraint can be applied since Product
C belongs to the active component Product B
and also Product E is contained within Product D
which is contained within the active component
Product B.
You cannot apply a constraint between two components belonging to the same sub-assembly if
this sub-assembly is not the active component.
You can apply constraints only between the child components of the active component.
You cannot define constraints between two geometric elements belonging to the same component

1
This assistant will warn you when you make mistakes putting constraints
2
Assembly Assistant
This warning appears when you have switched on the setting
“only use the published geometry” and try to select a non
published element for a constraint
This warning appears when you try to constrain two
elements which belong to the same component
3
(4)
This warning appears when you try to constrain a component
which does not belong to the active product

You will learn how to Update assembly constraints
Updating Assembly Constraints

What is Updating Constraints ?
Updating or regenerating constraints is the way to move components
into their assembled positions as specified by the constraints.
Here the coincidence constraint
is not updated
Here the coincidence constraint
is updated

Updating Constraints ...
The scope of the update can be applied to all constraints or just
individual constraints.
To update all the constraints and parts of
the assembly, click on the Update icon in
the Update Toolbar
To update an individual constraint, right-click on
a constraint in the tree or 3D and select Update
Update
needed
Update
done
Update
needed
Update
done
As a matter of practice, it’s a good idea to update
an assembly before saving it. This will enable
improved performance when opening assemblies,
especially when using Manual Update.
It’s also a good idea to update sub-assemblies
before activating another assembly. This avoids
unintended results when updating constraints.
1
1
2

Options for Updating Assembly Constraints
Updating can be Manual or Automatic. Updating can be applied to the
active level of the assembly or all levels.
Click on Options in the
Tools menu Select the “Assembly
Design” branch under
“Mechanical Design” node
Make your choices in
Update options
1
2
3
Select Manual because Automatic will modify your assembly
with each constraint creation

Handling Update Errors
When Updating, constraints are checked for conflicts where are also
called over-constraints.
Updating will display the Diagnosis Window if there are problems
such as over-constrained components
1
Select a record
2 Select Deactivate or Edit
Deactivate is a way to turn OFF
a constraint without deleting it.
Later the problem can be
examined and the constraint
deleted or re-activated
Edit displays the Constraint
Definition window where the
constraint can be edited or
reconnected to a different
element.
3

What is analysing Update ?
Analyzing Update allows you to know what are constraints and components in your
assembly that are updated or not and update them separately directly from where you are
constraints and
components to
be updated
Update Analysis
Dialog Box

Analysing Update (1/2)
Thanks to this command you will exactly know what constraints and
components are updated or not in your assembly and its sub-assemblies
1
Select Update from
Analyze menu
Update Analysis dialog box
appears and displays:
2
analyzed component
In Analyse tab
Constraints of the
analyzed component
that are to be updated
Sub Assemblies of the
analyzed component
Constraints of the
sub assemblies that
are to be updated
Representations of parts

Analysing Update (2/2)
This command displays also for you a selector which allows you to choose
and update any unresolved feature directly from where you are
3
In Update tab
List of the
unresolved
components
Select or multi-
select in the list
the features you
want to update
4 Click on
Update icon
5
Component is updated in the
geometry and does no more
appear in the list
6
Once you have
finished with Update
Analysis, Click on OK
This combo Box displays
all assemblies and
sub_assemblies available
for analyze

You will learn how to ease the creation of constraints using the Quick
Constraint capability
Creating Quick Constraints

What are Quick Constraints?
Quick Constraint is a way to create constraints while letting the
system partially decide which type of constraint to create.
You simply select two elements and let CATIA decide
which type of constraint to create
1
If you wanted a different type of constraint,
just click Change Constraint
2
You can set the preference for automatic
constraints using Tools + Options (Assembly
Design Node + Constraints tab)
3

1
Quick Constraint
2
Creating Quick Constraints
Creating a Quick Constraint is as simple as selecting two elements.

2 Change Constraint 3 Select the type
Changing a Constraint’s Type
You can change the type of any Assembly Constraint
whether or not it was created using Quick Constraint.
1 Select the constraint

You will learn how to choose the way you will put several constraints
one after the other
Multi Constraints Modes

When you have double clicked on a Constraint command, you will have three
ways to put the several constraints:
What are Multi Constraint Modes?
Default Mode when
no geometric
element is shared
between
constraints
Stack Mode when a
geometric element is
shared between all the
constraints
Chain Mode when
several geometric
elements are each
shared between two
constraint

1
This mode allows you to select two after two, geometric elements involved in
constraints
Select Default Mode in
MultiConstraint Mode Toolbar
2
Double click on the
Constraint you
want to apply
several times
3
Default Mode for Multi Constraint
(1)
Select elements
one after the
other, you will
see that as soon
as two elements
are selected, a
constraint is
created between
them
Once you have obtained all the needed constraints,
you must deactivate the command by clicking on it
4 (4)

Once you have obtained all the needed
constraints, you must deactivate the
command by clicking on it
1
This mode allows you to select only once a geometric element that is shared
between several constraints of the same type
Select Stack Mode in MultiConstraint
Mode Toolbar
2
Double click on the
Constraint you
want to apply
several times
4
Select the first geometric element that
will be shared between the next created
constraints
3
Stack Mode for Multi Constraint
(1)
5
Select one after another geometric
elements you want to constrain with the
shared element.
(3)
(4)
(5)

1
This mode allows you to select only once the shared element between two
consecutive constraints
Select Stack Mode in MultiConstraint
Mode Toolbar
2
Double click on the
Constraint you
want to apply
several times
3
Chain Mode for Multi Constraint
(1) Select one after t-he other the elements to be
constrained, specifying at each time the
parameters values, and each next constraint
will take as first geometric element the last one
selected for the previous constraint
Once you have obtained all the needed constraints, you must
deactivate the command by clicking on it
4
(4)
(3)

You will learn how to Hide assembly constraint symbols in the geometry
Hiding Constraints

What is Hiding Constraints ?
Hiding constraints can help remove clutter.
Cluttered screen
Un-cluttered screen
You can Hide individual
constraints
You can also Hide a
bunch of constraints at
the same time

Hiding Constraints ...
You can hide constraints as any other component of your assembly
just by selecting them and clicking on Hide/Show icon
You can either select the
constraint in the tree, in the
geometry or with selecting
tools such as Search
Hide/Show icon is either reachable
on View toolbar and View menu or
through the contextual menu of
the constraint

Hiding Individual Constraints
Hiding can be limited to one or more selected constraints.
1 Select a constraint in the tree or 3D 2 Select Hide/Show
You can hide more than one constraint at a
time by selecting with the mouse while holding
the [CTRL] key.
[CTRL] key

Hiding Constraints relative to a Component
An option in contextual menu of the component can be used to find and select all the
constraints which involve the component and can be subsequently hidden.
1
Right click on the
component in the tree 2 Select “Components Constraints”
3
4
Select Hide/Show
Constraints relative to the
component are selected

Hiding all the Constraints of an Assembly
You can hide at once all the constraints of an assembly.
1
Select first Constraint under Constraints
node in the tree
2 Keeping Shift Key Pressed, select last
constraint under Constraints node
3 Select Hide/Show
[Shift] key
(1)
(2)

You will learn how to filter Hide assembly constraint symbols in the
geometry
Filtering Constraints

What is Filtering Constraints ?
Constraint filter Options...
Displays the constraints
according to their type
Defines the filter level: if Conditional Filter is selected, the filters below
are available
Displays the constraints according to their status:
Verified only , unverified only or all of them
Displays the constraints on
the active product

Filter Constraints on an Active Product
Show only constraints of the active Product

Select or deselect the desired
types
Filter by Type (1/2)
You can filter and displays constraints according to
their type

Filter by Type (2/2)

You will become familiar with tools created to analyze an
assembly
• Measuring
• Computing Clash and Clearance
• Viewing Mechanical Properties
• Analyzing Constraints
• Analysing Degrees of Freedom
Analyzing an Assembly

You will learn how to measure an assembly
Measuring an Assembly

Distance and angles can be measured. Individual geometric
elements can also be measured.
What is Measuring an Assembly ?
Measuring distance between the
axis of two different components
Measuring the length of a line

1
Measure
Between
2
Optionally define how you want
to measure
3
Select the reference and target
elements
4a
Minimum distance and angle are
displayed in 3D and in the results
window
4b
The window also displays components of distance vector and
coordinates of Reference and Target points
Measuring between Items (1/2)
You can measure angle and distance between geometric entities.
To select sub-elements like the
axis of a hole, right-click and
select Other Selection...

1
Right click the
geometric element
2
Select Other selections
3
Expand the tree appearing in Other
selections dialog box
4
Select the sub
element
Measuring between Items (2/2)
You can select sub elements thanks to Other selections option.
5
Sub element is
now under
selection in
CATIA and
highlighted

1
Measure
Item
2 Select the item
Measuring Items
You can measure geometric items.
3
Properties of the selected item are displayed in
3D and in the results window
Click the Customize… button to
see the information that is
available for each type of element

1
Measure
Inertia
2 Select the item
Measuring Inertia
You can measure Inertia of components or geometric elements.
3 Properties of the selected item are
displayed in 3D and in the results window
Click the Customize… button to
see the information that is
available for each type of element

1 When Creating
your measure,
activate the Keep
Measure option
2 Each created measure will
be kept in the tree…
Keeping Measure
You can keep results of measures as features in the tree
… And in the Geometry … And be saved in
the CATProduct file
Those measure features
contain parameters that
can be used in any
formula of the
Knowledgeware

You will learn how to test for clash and clearance violations between
components
Computing Clash and Clearance

Clash analysis is used to check for interference between components.
Clearance analysis is used to ensure the proper clearance between components.
What is Clash and Clearance ?
A clash violation occurs when one
component penetrates another
component
A clearance violation occurs when a
minimum distance between components
is not respected
For more powerful clash and clearance analysis,
see the DMU Space Analysis workbench

2
Multi-select the components
using the [CTRL] Key
3b Click on Apply
4b Clashes are highlighted
1
Click on Compute Clash in
the Analyze menu
3a Select Clash from the list
4a
Clash violation is signaled
in the window
The Assembly Design workbench enables checking for
interference between two components.
Computing Clash between 2 Components

Multi-select the components
using the [CTRL] Key
1
Click on Compute Clash in
the Analyze menu
Select Clearance in
the list
Key in the
clearance value
3b
3a
2 3c Click on Apply
4b
Components not respecting the
clearance are highlighted
4a
Clearance violation is
signaled in the window
The Assembly Design workbench enables checking to
ensure clearance is respected between two components.
Computing Clearance between 2 Components

You will learn how to check the mechanical properties of parts and assemblies
Viewing Mechanical Properties

Mechanical Properties indicate physical characteristics of parts and assemblies.
What are Mechanical Properties ?
Structural Properties are assigned to
materials
Materials are assigned to parts
Mechanical Properties are computed based
on material that is assigned to parts
1
2
3

Mechanical Properties can be viewed, but not directly modified.
Viewing Mechanical Properties
1 2 Properties
3 Mechanical tab

Materials can be applied to components directly from the Assembly
Design Workbench.
Applying a Material to a Part of the Assembly
Select Apply Material
icon
1
2 Drag and drop the
material onto the
component
3
Drop the material when you have
this cursor on the
component you want to apply the
material to.
Material is applied
and appears in
specification tree of
the part

You will learn how to analyze the status of constraints and the
relationship between constraints and components
Analyzing Constraints

You will analyze a constraint by seeing its status and by identifying the
components involved in it.
What is Analyzing Constraints ?
A constraint is set between at less two components (except for the fixing constraint),
you will see them thanks to its display in specification tree or with the dependences
tree
Those are the components involved in
the constraint (CRIC_TOP.1 and Set1.1
are linked with Surface Contact.6)
A coincidence constraint can ( as any other type
of constraint ) be :
Not
updated
Deactivated Unresolved Active
In the Tree
In Constraint Analysis Dialog Box
Constraint Status can be seen :

Constraints can be examined to determine their status and how they relate to
other components.
Analyzing Constraints ...
The status of constraints can
be viewed to the tree
A global perspective of constraint
status can be viewed in an on-line
report
The relationships between components and
constraints can be dynamically navigated

Analyzing Constraints in the Tree
The status of constraints can be viewed in the tree.
This symbol indicates that the constraint not updated.
This symbol indicates that the constraint is deactivated.
This symbol indicates that the constraint is “unresolved” which means
either:
• The constraint is broken (for example, related component deleted); or
• The constraint is impossible (for example, geometry modified and
constraint no longer possible)
Select the plus-sign (+) on the
Constraints branch to expand
the branch
1

Analyzing Constraints in the on-line Report
2
Select Constraints… from
the Analyze menu
Activate the assembly to be
analyzed
A global status of constraints can be viewed for the active assembly.
The Constraints Analysis Window
appears and shows the status of the
constraints
1

Analyzing Constraint Relationships
The relationship between constraints and components can be
dynamically navigated.
2
Select Dependence… from
the Analyze menu
Activate the assembly to be
analyzed
1 3
Right-click on a constraint and select Expand All to see which
components are associated with the constraint
You can also expand a
component, even the
top assembly

You will learn how to analyze Degrees of Freedom on a component
Analyzing Degrees of Freedom

There are 6 Degrees of Freedom for each instance:
3 Degrees of Rotation and 3 Degrees of Translation
What is a DOF ?
When there is no constraint on a instance. All Degrees are free
When a instance is full-constrained, all Degrees are fixed.
If you decide for example to fix a instance, there is
no degree of freedom

Degrees of freedom Analysis
You can select one instance and analyse its degrees of freedom

You will learn how to edit parts in-context of an assembly
• Designing in-context of an assembly without external links
• Aligning Components for Sketching
• Using Local Axis for Snapping
Editing Parts in an Assembly

You will learn how to design a part in-context of an assembly
without External References
Designing in-context
of an Assembly without external
links

Part features and sketches can be design in-context of an assembly.
What is Designing in-context of an Assembly ?
Parts can be sketched on the face
of neighboring components
3D elements from other components
can be projected onto and intersected
with the sketch plane
Sketch constraints can be defined
using elements in other components
Features can be limited
up-to other components
Parts can be edited in
context of an assembly

Designing in-context of an Assembly without links
Part features and sketches can be design in-context of an assembly with the Keep
link with selected object option deactivated.
No associativity in case
of Design modifications
Design in-context : these sketch
elements are copied from the Reference
Part ones into a Open Body.

Designing in-context of an Assembly with links
Part features and sketches can be design in-context of an assembly with the Keep
link with selected object option activated.
For more details, see the Assembly Design
Advanced Course to design in-context with
associativity.
Notice the green
color of the
wheel icon
Keep links in case of
design modification

2
Double-click the branch that is
just below the one you
expanded
The part is active and the last
workbench used to edit a CATpart
document is displayed
Editing a Part
In order to edit a part, the part must be activated.
Select the plus-sign (+) next to
the part you want to edit
1
The branch represents the
instance of the part
The branch represents the
actual part
Another way to easily activate a part
is to double-click the part in 3D

3 Select the Sketcher icon in the
Part Design workbench
4 Select a face on a component
Sketching on the Face of a Component
A part can be sketched on the face of another component.
5 Sketch on the face
Notice that a copy of the face
appears in the Open_body of the
active part

6
Select one element from the sketch and
another from a neighboring component
7
Define a constraint just as you would
when constraining two elements
within the sketch
Defining Sketch Constraints using other Components
Sketch constraints can be defined using elements in other
components.
Notice that a copy of the element
from the other part appears in
the Open_body of the active part

1
Project 3D
Elements
3
Isolate the projected element from the original
element by right-clicking the element and
selecting xxx.object + Isolate
Projecting 3D Elements onto the Sketch Plane
3D elements from neighboring components can be projected
onto the sketch.
2
Select an element from a
neighboring component
You can also project other types of
elements such as points and faces
(which projects the edges of the face)

Intersecting 3D Elements with the Sketch Plane
3D elements from neighboring components can be intersected
with the sketch.
1
Intersect 3D
Elements
2
Select an element from a
neighboring component
You can also intersect other types of
elements such lines (which creates a
point at the intersection)
3
Isolate the projected element from the original
element by right-clicking the element and
selecting xxx.object + Isolate

Limiting Features up-to other Components
You can select geometric elements of other components to design features of your
part
1
When defining features such as a
pad, set the limit up-to-plane or up-
to-surface
2
Select a face in a neighboring
component

You will learn how to align components so that the sketch plane of one
component is parallel to another component that is being sketched on
Aligning Components for Sketching

Sometimes it is convenient and intuitive to align a part that is being sketched with
another component so that the sketch is parallel to the other component.
What is Aligning Components ?
However, sometimes the part being sketched is not
oriented so that it is parallel to the component
being sketched on
When designing in-context you will find it
useful to sketch on the face of another
component
The Snap function can be used to align the
part being sketched so that it is parallel to
another component
In this case we want to sketch a
new part on this face
1
2
3

Snapping Components into Alignment
The Snap function provides a quick way to align components.
Snap
1
2
Select the planes and/or faces that
are to be made coplanar
3
Click on the
green arrow to
change the
orientation of
the moved part
4
Click
somewhere in
the geometric
space to
validate the
position
5
Components
are correctly
positioned
relative to each
other
Notice that
first selected
component
will move

You will learn how to use local axis to snap components to each other
Using Local Axis for Snapping

Why Snapping Local Axis?
The Snap function provides a quick way to align components but lines and points in the
geometry are needed for that.If you do not have any, Local Axis are useful
In this assembly, to build the
cylindrical part perpendicular
to the upper surface of the
other part, we needed Local
Axis

Snapping Local Axis of Components into Alignment
The Snap function provides a quick way to align components and you
can select planes, axis and point of Local Axis System to perform it.
Snap
1
2
Select the planes and/or faces that
are to be made coplanar 3
Select the green arrow to invert the
direction of the component
4
Click somewhere else in the
geometry to validate
5
Planes are now aligned
6 For snapping you can select on
Local Axis System:
Planes Axis Points

You will learn how to manage components of your assemblies
• Using Visualization mode
• Deleting Components
• Duplicating Components
• Replacing Components
• Restructuring Components
• Reordering Product Structure
Working with Components

You will learn how to use Visualization Mode to improve performance.
Using Visualization Mode

What is Visualization Mode?
Substantial performance improvements can be gained by using a light form of parts
and models, called Visualization Mode. Loading an assembly is faster when using Visualization
Mode.
Parts and models in Design Mode are fully
loaded in memory, fully functional, and
completely accessible.
Notice that the screw branch is expandable
and therefore the PartBody is accessible.
When parts and models are in Visualization Mode, just a subset of the
data is loaded in memory. The remaining data is loaded as needed.
Assemblies can be loaded with parts and models:
• Fully resolved, called Design Mode; or
• In a light form, called Visualization Mode
Parts and model in Visualization Mode
are partially loaded in memory and
therefore partially functional and
accessible.
Notice that the screw branch is not
expandable and therefore the PartBody
is not accessible.

Turning ON the cache system will cause CATIA to automatically load parts and models
in Visualization Mode when opening assemblies.
User Setting : Turning On the Cache (1/2)
1
the Tools menu
Select “Cache
Management” tab
2
3
Select “Product Structure” branch
under “Infrastructure” node
Activate Work with the cache system
4
5
The cache system is not activated until
CATIA is restarted

User Setting:Turning On the Cache (2/2)
Work without the Cache System Work with the Cache System
You work with the
cgr files:
Notice that the
branch is not
expandable and
therefore the
PartBody is not
accessible.
You can edit items
Right-clicking selecting Design Mode also switches the part or model to
Design Mode:

Parts and models can be manually switched to Design Mode.
Manually Switching to Design Mode
When opening an assembly, parts and
models are in Visualization Mode
Double-clicking a part or model in an
assembly switches it to Design Mode.
Note that all instances of the part or model
switch to Design Mode when any instance is
switched.
1
2a
Right-clicking selecting Design Mode also
switches the part or model to Design Mode
2b
Right-clicking an assembly and selecting Design Mode
switches all parts and model in the assembly to Design Mode.

Parts and models automatically switch to Design Mode when defining Assembly
Constraints.
Constraining Parts in Visualization Mode
Parts and models automatically switch to Design Mode
after assembly constraint is defined.
When a constraint icon has been selected, the mouse
cursor has a feather on it when hovering over a part or
model that is in Visualization Mode.
When opening an assembly, parts and
models are in Visualization Mode
2
3
Activate the option Automatic Switch to Design Mode
1

1
This setting allows you to put constraints between components that are on
visualization mode
2
Automatic Switch to Design Mode
Check that the
“Automatic switch to
Design Mode” option is
activated
Around a geometry , the
cursor will have this shape
Click the geometry
3
Select the Constraint
Command
Note that constraint
commands are available
even if no components are
on Design mode
4 The Component on which you selected a
geometric element is now on Design Mode.
Select next element.
5 Last component is now on Design
mode and constraint is created.
(2)

In order to update constraints, parts have to be in Design Mode. Use
Analyze + Dependencies to identify the parts in the constraint “network”.
Select Dependencies…
from the Analyze menu
Select the component that
was repositioned
1
3
4 The graph lists the parts and model that should be switched to Design Mode
2
Right-click the part or model and select Expand All to see
the components in the network of constraints
Updating Assembly Constraints and Visualization Mode

You will learn how to delete components and their associated constraints
Deleting Components

Removing a component from an assembly is called “deleting the component”.
What is Deleting Components ?
Deleting a component removes the
component from the assembly
But deleting a component does not delete
the referenced file from the hard drive

2 Press the <DELETE> key
Uncheck this box to not delete the
assembly constraints associated with
the component
Deleting a Component
When deleting a component, you decide whether or not to delete the
constraints associated with the component.
In the tree of 3D, select the
component to be deleted
3
These constant will be deleted
Components can also be deleted by right-clicking the
component and selecting Delete from the contextual menu
1

You will learn how to duplicate components
Duplicating Components

1
2
3
Right-click the
component to be copied
Copy
Right-click the assembly in which you
want to paste the component
After pasting there are two
instances of the part
Copy-and-Paste a Component
Copy-and-Paste is an easy way to duplicate a component.
4 Paste
You can also use shortcuts
Another way to copy-and-paste a component
is to press [CTRL] while dragging the
component onto the assembly.
[CTRL] key
Instance name

Setting Copy-and-Paste Options
You control whether constraints are copied-and-pasted when
copying-and-pasting components.
1
the Tools menu
Click Assembly-Design
2
3
Set the Paste components option to either:
4
•Without the assembly constraints
•With the assembly constraints only after a
Cut
Copying constraints when copying a component will cause both
components to be constrained in exactly the same way. This is okay, but
you will have to manually edit or delete and recreate some constraints.
Two Lug Nuts with
a coincidence
constraint to the
same Stud
Select Constraints Tab

Instanciating Multiple Instances of a Component
Components can be duplicated along a line. Beware that in this in
case the components are not automatically constrained.
Define Multi Instanciation
1 Select a component
2 Specify the number of instances and
space between them
3a
Select a direction
3b
Use the Fast Multi Instanciation
icon to re-use the Default multi-
instanciation definition

Creating a Pattern of Components (1/3)
Patterns in parts can be used to automate the duplication of a
component and creation of constraints.
Reuse Pattern
1 Select a component
Select the pattern to follow
Specify the constraints to re-use
2
3a
3b
Notice that the constraints for the duplicate components are correct.

Keep link with the pattern….
The reuse pattern command create an Assembly Feature « Pattern » that is associative
in case of modification of the part design pattern that was used as input.
Component to instantiate Pattern
Disk
Lug Nut

When you modify the ‘instances’ in the design pattern, the assembly pattern is
« out of date » and the update of the assembly will add/delete generated
components

Symmetrical Sub-Assemblies

What Symmetrical Sub-Assembly ?
Create a symmetrical sub-assembly from an original one, based on a symmetry
plane.
Generation:
The result of the generation of a symmetrical sub-assembly is another sub-
assembly with a similar product structure.
The User chooses between both options ,
The parts building the symmetrical sub-assembly are :
•Either a symmetrical part from the source part. This involves creating a new part,
outside any assembly context, with a new « PartNumber ». A typical example is the
left door in a car, relatively to the right door.
•Either a new instance of the source part, in a position symmetric to the original
part. A typical example is a car’s front left wheel, relatively to the front right
wheel.

Creating a Symmetry on Component (1/2)
Select the icon
You can find it on the ‘Product Structure Tools’ Toolbar
1
2
The Assembly Mirror Wizard dialog box appears:
The reference plane is now displayed in green.
Select the mirror plane
3 Select the sub-assembly to be mirrored

Creating a Symmetry on Component (2/2)
By default , CATIA create a new component by each Part
4 Results:
4 components created
New Part Number

Create New Instances
On this following example , you need to create
new instance about the Wheel and Disk Parts.
Select one component and activate
Symmetry wih new instance option
New instance
When the user chooses to create a new instance of a source part, at a mirrored position,
a new instance is created in the symmetrical sub-assembly, then its position is chosen
with respect to the symmetry plane, at creation time.
Only reference plane of the part can be used in
determining the transformation

Keep Links
Once the symmetrical sub-assembly has been generated, changes in
the source sub-assembly shall allow updating it
« FORM » associativity:
A change in geometrical shape of the source part
leads to update the symmetrical part.
« POSITION » associativity:
A change of relative position of a component of the
source sub-assembly leads to update the position
of the symmetrical component in the symmetrical
sub-assembly.
« STRUCTURE » associativity:
A change in structure of the source sub-assembly (adding/removing
components) leads to update the structure of the symmetrical sub-assembly.

You will learn how to replace components
Replacing Components

Replacing a component is a shortcut to deleting a component and
adding another component in its place.
What is Replacing Components ?

Replacing a Component
A single instance of a component can be replaced.
Right-click the component to be
replaced
1
2 Replacement Component 3b Double-click the file
3a
Choose a filter if desired (for example, CATPart,
CATProduct, model, etc)
Don’t forget that you have to manually
revise any references (such as constraints)
to the component that was replaced
Notice that the instance
name is not modified
This option make replaced all instances that
have same reference as selected
component

Reconnecting a Constraint (1/2)
A constraint can become unresolved after a replacement of a component
or connected to a wrong geometric element.You have the possibility to
redefine geometric elements involved in it.
Edit the constraint you want to
reconnect
1 2 Expand the dialog box
4 Click on Reconnect
3
Select in dialog box geometric
element to reconnect
5
2 x
(1)
(2)
(3)
(4)

Reconnecting a Constraint (2/2)
The Constraint dialog box let you have a look at geometric elements
involved in it.
Select the new connected
geometric element
5
Edited constraint is now connected to
the just selected element.You can
Click on OK and Update the
constraint
6

You will learn how to move components from one assembly to
another assembly while maintaining constraints
Restructuring Components

Sometimes it is necessary to restructure components by moving components
from one assembly to another assembly.
What is Restructuring Components ?
Move to sub-assembly
Move to parent assembly
Move to peer assembly

Setting Cut-and-Paste Options
You control whether constraints are maintained when moving a
component to another assembly.
1
the Tools menu
2 Select Assembly Design
node under Mechanical
Design branch
Set the Paste components option to:
3
•With the assembly constraints only after
a Cut

Moving a Component to Another Assembly
Components can be dragged to another assembly while maintaining constraints.
1 Click the component and hold
down the left mouse button
2
Drag the mouse over the
target assembly and release
the mouse button
In this case two constraints are also moved to
the target assembly because both associated
components exist in the target assembly
The component is moved to
the target assembly
3

You will learn how to change the order in which components are
displayed in the tree
Reordering Product Structure

What is Reordering Product Structure?
This command allows you to reorder components display in the tree under a
selected product
Tree to reorder Reordered tree
a
b

1
2
This command allows you to reorder components display in the tree under
selected product
3a
Product Structure Reordering (1/2)
Select the Graph Tree
Reorder Command
Select the Product in which
you want to reorder
components
(2)
Select the Component you
want to reorder
(3)
4a
Click one of these arrows to
move the selected component
of one level

3b
Select another component
to reorder
4b
Click this icon and click the
component above which you
want to place the selected
component
5
Click Ok to get the
reordered tree
6 Here is the reordered tree
Product Structure Reordering (2/2)
There are two ways available to reorder components in the tree

• Flexible Sub-Assemblies
What can you do with Flexible Sub-Assemblies?
Managing Flexible Sub-Assemblies with Several Levels
• Propagating Position to Reference
You will become familiar with positioning components in an
assembly using assembly constraints
Flexible Sub-Assemblies

You will learn how to get a Flexible Sub-Assembly and to see impacts
on positioning matrix and constraints
Flexible Sub-Assemblies

A flexible Sub-Assembly is a Sub-assembly whose child components can be moved
disregarding the fact it is not the active component. Relative positions of its child
components can be different than those stored in the reference CATProduct File.
What are Flexible Sub-Assemblies?
Icon with purple
wheel means
Flexible Sub-
Assembly
There you can see four instances of
Leg sub-Assembly : notice that
components of leg are not positionned
the same way in each instance, it is
possible because instances of Leg
Assembly are flexible
Leg.1
Leg.2
Leg.3
Leg.4
Relative positions of
components in the
reference of the Sub-
Assembly
Leg

1
Rigid/Flexible sub-Assembly command is a switch: you can have components of the sub-
assembly in same relative position as in the reference CATProduct (Rigid Sub-Assembly) or
in relative positions that are contextual to the assembly (SoftSub-Assembly)
Select the Sub-Assembly
2
Flexible/Rigid
Sub-Assembly
3
Making a sub-Assembly flexible
(1)
Selected Sub-
Assembly is now
Flexible
Note that you can make the sub-Assembly rigid again using
the same icon
Purple wheel
means means
flexible instance
(2)

You can position components by freely moving them with the compass or by
constraining them. In both cases Rigid/Flexible state is important.
Freely moving Components
Positioning Components of a Flexible Sub-Assembly(1/2)
In this case the compass has
been put on a component of a
Rigid Sub-Assembly.
In this case the compass has
been put on a component of a
Flexible Sub-Assembly.
Root assembly is active, so the
compass will drag the whole
Rigid Sub-Assembly
Root assembly is active, but as
the sub-Assembly is flexible, the
compass will only move the
selected component

Relative Positions of components of a Flexible Sub-Assembly are stored with
instance informations in containing CATProduct.
Constraining Components
Positioning Components of a Flexible Sub-Assembly(2/2)
When you create a
constraint between :
a component of the
active assembly …
… And a component of
a rigid sub-assembly …
Constraint involves the
component and the whole
Rigid Sub-Assembly
And a component of a
Flexible sub-assembly …
a component of the
active assembly …
When you create a
constraint between :
Constraint involves the component
and the selected component of the
Flexible sub-assembly
flexible
instance

There are two types of structure when you use flexible Sub-Assemblies
What is Mechanical Structure?
Product Structure Tree shows which
assemblies and sub-assemblies
Parts and constraints belong to
Mechanical Structure Tree
shows what components you
can constrain together (they are
at the same level)
Components and
constraints of Flexible
Sub-Assemblies are
considered as direct
childs of the root
assembly in mechanical
Structure tree
Flexible Sub-assembly
does not exist anymore in
Mechanical Structure tree
Product Structure Mechanical Structure

There are two types of structure when you use flexible Sub-Assemblies
Viewing Mechanical Structure
1
Activate the Assembly or
Sub-Assembly you want
to analyze
2 Select Mechanical Structure
from Analyze menu
Mechanical
Structure of the
instance
Mechanical
Structure of the
reference
Combo
box

You will learn to manipulate Flexible Sub-Assemblies
What can you do with Flexible Assemblies?

Once the sub-assembly is flexible, Numerical Value, Activity status, Orientation (Same
or Opposite), Driven/Driving property can be overload to modify locally its internal
definition, or deal with under/over constrained situations
What can you Overload with Flexible Sub-Assemblies?
Flexible Sub-Assembly
Rigid Sub-Assembly

Activate / Deactivate Status
Concerning methodology using flexible sub-assemblies, you can change the
Activity Status on a constraint
flexible Sub-Assembly

Numerical Value
On a flexible sub-assembly, you can modify numerical values without
impacting others instances
Flexible Sub-Assembly
Rigid Sub-Assembly

Propagating Position to Reference

Propagating Position (1/2)
1 Modify position of the Flexible Base Instance.
: flexible instance
: rigid instance
This Product contains 2
sub-assemblies :
Base.CATProduct
Base_unit.CATProduct
Flexible sub-assembly

2 Apply overloaded position to reference
 Select the flexible Base instance
 MB3+ ….object+Propagate
position to reference
Propagating Position (2/2)
Result : all rigid instances
should have the same position
than the flexible one.
Internal position of flexible
instances are not impacted by
the command.
V5R8

To Sum Up ...
You have seen CATIA V5 Assembly Design
User interface:
• How to access the workbench
• Its user interface and tools
• The terminology that will be used
• The general design process
... and Basic functions:
• How to add components
• How to position components
• How to analyze an assembly
• How to design a part in context of the assembly
• How to manage components
• How to manage Flexible Assembly
Sum Up …

Catia assembly design.ppt

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