catia whole

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Generative Shape

Design

CATIA Training

Foils

Version 5 Release 8 January 2002 EDU-CAT-E-GSD-FF-V5R8

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Copyright DASSAULT SYSTEMES 2002 2

Course Presentation

Objectives of the course

This course covers tools for surface design included in the Generative Shape Design

Workbench that are not present in the Wireframe and Surface Design Workbench. At the

end of the course, the student will be able to model complex fillets and analyze surface

quality.

Targeted audience

Mechanical Designers

Prerequisites

Wireframe and Surface Design

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 Introduction to Generative Shape Design

p.6

 Creating Wireframe Geometry

p.12

Creating an Extremum

p.13

Creating a Polar Extremum

p.21

Creating a Reflect Line Methodology

p.29

Creating a Spine

p.39

Creating a Parallel Curve onto a Support within GSD

p.

Extracting Multiple Edges from a Sketch

p.

Tools for Wireframe Geometry Creation

p.

 Creating Surfaces

p.67

Creating Swept Surfaces

p.68

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1. Performing Operations

p.67

Joining Elements

p.

Healing Elements

p.

Smoothing Curves

p.

Extracting Elements

p.

Federating Elements

p.

Creating Fillets

p.

Inverting Orientation

p.

Creating Laws

p.

Using Analysis Tools

p.

Managing Features and Open Bodies

p.

Hybrid Design

(Working with Hybrid Parts)

p.

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Generative Shape Design Workbench

Generative Shape Design Interface

Generative Shape Design Terminology

1 hour

In this lesson you will see V5 Generative Shape Design user interface

and basic functions

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Copyright DASSAULT SYSTEMES 2002 6 From the MENUBAR

Start/Shape/Generative Shape Design

Accessing the Workbench

1

2

By clicking on the current Workbench icon (top right) to access the Favourite Workbenches window.

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Shape Design tools... Sketcher access... Part Tree Standard tools All Non-Solids (i.e. Points, Curves, Surfaces) grouped under “

Open

Body

”

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The PartBody is the default Body for a Part where Solids are stored The Open Body is where non-solids (points, curves, surfaces) are stored

Terminology

A Part is a combination of one or more Bodies and Open Bodies

Wireframe features

Surface features

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From Assembly > create a new part (Top-down approach)

or

Create a new part > insert in assembly (Bottom-up approach)

General Process

Go into the Sketcher to create the planar Wireframe Geometry

Create Surfaces on

the Wireframe _{required 3D Wireframe}Use GSD to create all

Geometry

Optional : Join Multiple Surfaces then Offset a solid

4 3

2 1

5

Use GSD to create Planes in 3D to support 2D Wireframe

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Creating Wireframe Geometry

In this lesson, you will learn how to create all types of Wireframe

elements.

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WFS Wireframe versus GSD Wireframe

Wireframe & Surface Design and Generative Shape Design are two workbenches which have many common functionalities.

Within GSD you will discover new functionalities that are not in WFS and also advanced capabilities in some functions that exist in both workbenches.

Functionalities specific to the Generative Shape Design workbench. WFS GSD Functionality common to both workbenches but with more capabilities within GSD.

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Review of WFS Wireframe Geometry

You can review the tools covered in the Wireframe & Surface Design Course which

are also included in the Generative Shape Design Workbench.

Creating Points in 3D Creating Lines in 3D Creating Planes in 3D Creating Curves in 3D

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In this Skillet you learn what is an Extremum and how to create it.

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Why Create an Extremum?

In order to help CATIA find the maximum or minimum point of a curve or surface along any direction chosen by the user.

Maximum Extremum on a Curve along the Z Axis

Minimum Extremum on a Surface along the X Axis

The element might be a sketch, a 3D curve or line, a surface or a solid face.

Maximum Extremum on a solid face along the Z Axis

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1

2

Select the Extremum Icon.

Creating an Extremum

5

Select the element on which to find the Extremum.

3

Click OK to confirm. The Extremum

is added to the specification tree Select a line or a plane (normal

direction) to specify the direction to evaluate the Extremum

Select Max or Min according to your requirement.

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Additional Information on Extremum

If the element is a surface, you may specify two others optional directions.

If the Element is a surface, according to the chosen direction you can obtain a curve or a line as Extremum.

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In this Skillet you learn what is a Polar Extremum and how to create it.

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What is a Polar Extremum?

Any planar curve can be defined with its polar equation (relation linking the radius and the angle).

The polar extremum function allows you to find the points on the curve corresponding to : The minimum radius from a specified origin :

The maximum radius from a specified origin :

The minimum angle regarding to a specified direction :

The maximum angle regarding to a specified direction :

The polar extremum is calculated in an axis system defined by :

- An origin.

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Creating a Polar Extremum

1

_{Select the Polar Extremum}

Icon.

2

Select the type of _{polar extremum you}

want to create.

3

Select the planar contour _{on which you want to}

create the polar extremum and its supporting plane.

4

Select _{point from the polar}the origin

extremum will be calculated.

5

Define the reference _axis.

6

Click OK to confirm _{the polar extremum}

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Creating a Reflect Line Methodology

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What is a Reflect Line

Reflect lines are curves for which the normal to the support surface in each point presents the same angle with a specified direction. It is very useful to find the parting plane of a complex surface.

If we perform a Draft analysis on this part, we can see, thanks to the red areas that the part is non extractible.

Thanks to the Reflect Line curve, we can cut the part in two extractible parts.

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1

2

Select a support surface and a direction.

Creating a Reflect Line

4

_{Click OK to confirm reflect line creation}

Key in an angle representing the value between the selected direction and the normal to the surface.

Support

3

Reflect lines

You can define one of the X,Y or Z axis by opening a contextual menu in the Direction field.

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Creating a Spine

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What is a Spine ?

Profile

Guide Curve

In this Swept surface, the Spine is, by default, the guide curve. Each section of the swept surface is perpendicular to this Guide Curve

Swept sections are perpendicular to the guide curve

The swept sections may be oriented by another Spine (not the default one). For instance you want to get the swept sections perpendicular to the green spine:

Spine

Swept sections are perpendicular to the Spine.

For the Swept and Lofted surface, there is a default spine (the guide or a computation from the guides). If you want to fix an orientation for your surface sections you will have to define a Spine.

The Spine icon will allow you to create a curve that will be use later as a spine There are two ways to build a spine :

Curve normal to a list of ordered

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1

2

Select the Spine Icon.

Creating a Spine from planes and planar curves

Successively select planes or planar profiles.

3

Click OK to confirm.

The Spine is added to the specification tree. You can also select a start point.

The point is projected onto the first plane as the spine starting point.

Use these three buttons to replace, delete or add a plane or a profile.

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1

2

Select the Spine Icon.

Creating a Spine from Guide Curves

Click in the field Guide

3

Click OK to confirm. The Spine is added to the specification tree.

Use these three buttons to replace, delete or add a plane or a profile.

Select the Guide Curves

4

Sweep using the default spine (guide curve 1)

Sweep using the user created spine

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Creating a Parallel Curve onto a Support Within GSD

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1 Creating a Curve Parallel to another on a Support (1/3)

2

Choose the parallelism type :

Geodesic :

The distance between the curves will be calculated taking the support curvature into account. Reference curve Euclidean Parallel Curve Geodesic parallel curve Support Euclidean :

The distance between both curves will be calculated without taking in account the support curvature.

Reference curve Parallel Curve Geodesic Euclidean

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3 Creating a Curve Parallel to another on a Support (2/3)

Select the reference curve and the support plane or surface.

Click OK to continue

The created curve is defined as an Object, i.e. the reference for creating the other

Specify the Offset by entering a value or using the graphic manipulator (green arrows).

4

Reference curve Support

If you want to create several parallel curves separated by the same offset check the option

Repeat object after OK

If you have chosen the euclidean parallel type, you can choose to offset the curve at a constant distance or according to a law.

5

6

Check here to create two parallel curves symmetrically in relation to the reference curve.

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7

Define the number of parallel curves to be created

8

_{Click OK to confirm parallel curve creation}

• As many parallel curves as indicated in the Object Repetition dialog box are created, including the object parallel curve. • The parallel curves are separated from the object line by a multiple of the offset value.

• The curve instances are grouped in a new Open Body if you have checked the option.

Creating a Curve Parallel to another on a Support (3/3)

Object parallel curve

Parallel curve instances in a new Open Body

You can choose to create or not the instances in a new Open Body.

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Extracting Multiple Edges from a Sketch.

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1 Extracting Multiple Edges

2

Select the Extract Multiple Edges icon

If you have a sketch containing several elements, you can extract a subpart of these elements to create geometry.

Select the geometry of the multi profile sketch that you want to extract

3

Click on OK, the extract is added to the _{specification tree}

Click on this button to delete a sub element of the list

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Tools for Wireframe geometry creation.

Stacking Commands

Work on Support

Now let us look at some Wireframe tools common to the WFS and GSD

Workbenches ...

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You will learn how to stack commands while creating

wireframe elements.

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What about stacking commands ?

You can create the following construction elements: - points, - planes, - intersections.

- lines, - projections,

You have access to the stacking commands capability while creating:

- points, - circles, - translations,

- lines, - conics - rotations,

- planes, - corners, - symmetry.

Why Do You Need to Stack Commands ?

Stacking commands allows you to create construction elements while creating an element which requires those construction elements.

Using mouse button 3 you display a contextual menu listing all the elements you can create using the stacking commands capability.

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You define the parameters of the construction element.

Let ’s see now the way to stack

commands...

Stacking Commands…

While creating an element you may need a construction

element that you will create on the fly.

The construction element is created and selected at the same time.

When using the stacking command capability you can check the status of the stack in the Running

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1

2 Stacking Commands (1/4)

Select the type of plane you want to create.

When you create some wireframe elements (point, line, plane, circle, corner, conic) or when you perform a translation, a rotation or a symmetry on an object you can create on the fly the

missing construction elements, i.e. points, lines, planes, intersections or projections. In the following example you will see how to create a plane from scratch.

3

Using mouse button 3 click in the Point field and select the Create Point option.

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Stacking Commands (2/4)

4

Define the parameters to create the point.

The status of the stacking commands is also displayed in the Running Commands window.

5

Click OK to accept point creation.

The Plane Definition window is displayed again with Point.1 in the Point field.

The Point button next to the Point field allows you to edit the point parameters.

6

Using mouse button 3 click in the Line field and select the Create Line option.

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Stacking Commands (3/4)

7

Define the parameters to create the line.

The status of the stacking commands is also displayed in the Running Commands window.

8

To create the points needed for the line you can also use the stacking commands.

In that case the Running Commands window will look like this:

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Stacking Commands (4/4)

9

Once the two points are created click OK to accept the line creation.

The Plane Definition window is displayed again with Line.1 in the Line field.

The Line button next to the Line field allows you to edit the Line parameters.

10

Click OK to accept the plane creation.

If you want to modify a parameter of the plane you can also double-click on its identifier in the specification tree.

Point.1

Point.2 Point.3

Line.1

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You will learn how to define a planar or non-planar support,

work on it with or without a grid and snap to a point.

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What about support ?

• If you define a plane as a support a grid is displayed and

positioned in the plane of the screen. In that case you have access to the ‘Snap to Point’ capability.

• If you define a surface as a support the elements created after

selection of the surface will be located on the surface by default.

Why Do You Need to Work on a Support ?

You can select a plane or a surface to use it as a support for further element creation.

Support plane = YZ With the ‘Snap to Point’ capability the created points are located at the nearest intersection of the grid.

Support surface = Extrude.1 When you create a point after selecting the surface as a support the Point Definition window automatically displays the option ‘On surface’.

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Working on a Support – Plane Support (1/3)

1

2

Select the plane you want to define as a support, here the YZ plane.

The Work on Support window is displayed. A Working support.1 feature is added to the specification tree under the Working supports entry.

By default the last created working support (current) is displayed in red in the specification tree. The ‘not current’ working supports are displayed in blue.

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Working on a Support – Plane Support (2/3)

The Work on Support window changes and displays several options to define the grid.

Define the number of steps in a grid subdivision

Selected plane

Define the total length of the grid subdivision

Check this option if you want a different primary spacing in the second direction Define which axis is taken as H direction in the 2D plane

3

Click OK to confirm grid creation.

Set the grid visualization parallel to the screen

If you enter coordinates when the ‘Snap to point’ icon is active, the system does not take the grid into account.

4

If you want your cursor to move

directly to an intersection point of the grid click on the Snap to Point icon.

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Working on a Support – Plane Support (3/3)

Here you are creating a point. Note that :

- the point type is automatically set to ‘On plane’,

- the cursor points only on the grid intersection points.

Create an element on the support.

5

Exit the working support :

6

Using the Working Supports Activity icon

Using the Set as Not Current option in the contextual menu

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Working on a Support – Surface Support (1/2)

1

2

Select the surface you want to define as a support, here the extruded surface.

The Work on Support window is displayed. A Working support.1 feature is added to the specification tree under the Working supports entry.

By default the last created working support (current) is displayed in red in the specification tree. The ‘not current’ working supports are displayed in blue.

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Working on a Support – Surface Support (2/2)

3

Click OK to confirm grid creation.

Here you are creating a point. Note that the point type is automatically set to ‘On surface’.

Create an element on the support.

4

Exit the working support :

5

Using the Working Supports Activity icon

Using the Set as Not Current option in the contextual menu

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Creating Surfaces

In this lesson, you will review all the Surface creation tools that were

covered in WFS and that are also available in the GSD Workbench

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What about surfaces ?

You can create a surface from:

- a line, curve or sketch - other surfaces

You can use basic surfaces either to create a new part or to complete the design of a solid part

Surface of revolution created from a profile (Spline) and an axis of revolution

Offset surface created from another surface and a direction

For each type of surface you will also define its limits or the angle of revolution

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WFS Surfaces versus GSD Surfaces

Wireframe & Surface Design and Generative Shape Design are two workbenches which have many common functionalities.

Within GSD you will discover new functionalities that are not in WFS and also advanced capabilities in some functions that exist in both workbenches.

Functionality specific to the Generative Shape Design workbench.

Functionality common to both workbenches but with more capabilities within GSD.

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Review of WFS Surfaces

You can review the tools covered in the Wireframe & Surface Design Course which

are also included in the Generative Shape Design Workbench.

Creating a Surface from a profile

- Creating a Extruded Surface

- Creating a Surface of Revolution

-

Creating a Sphere

Creating a Surface from Boundaries

- Creating a Fill Surface

- Creating a Blend Surface

Creating a Surface from another Surface

- Creating an Offset Surface

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Explicit Swept Surfaces

Implicit Swept Surfaces

You will learn how to create Explicit and Implicit Swept Surfaces

within the Generative Shape Design Workbench

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You will learn how to create swept surfaces using Any Profile

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1

2

3

Confirm swept surface creation

Creating an Explicit-type Swept Surface (1/7)

Select the guide curve and the profile.

You can then choose to give a reference plane or surface (Reference tab) or to select another guide curve and anchor points (Second Guide tab).

If no spine is selected the guide curve is used as spine. Select the Sweep Surface icon.

By default, the swept profile is constant in each section along the guide curve.

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Creating an Explicit-type Swept Surface (2/7)

You can define a reference

surface to control the position of the profile along the sweep.

Using a reference surface :

You can define a law to drive the angle evolution between the profile and the reference surface

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Using positioning and a reference surface :

Using positioning and a reference surface : The guide curve axis system is now oriented regarding the reference surface orientation :

Using positioning :

The profile is oriented in the guide curve axis system.

Using no positioning :

When the profile position is fixed with respect to the guide curve, the sweep lies on the profile and on the guide curve (if it intersects the profile) or on the parallel to the guide curve crossing the profile (minimum distance).

Creating an Explicit-type Swept Surface (3/7)

You can position the profile with the guide curve.

Using the Position profile mode, the reference is no more the profile but the Guide Curve.

Green axis-system :

current profile orientation

Grey axis-system : profile reference axis

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Creating an Explicit-type Swept Surface (4/7)

In the Position profile mode you can display parameters to modify the position of the sweep profile on the guide curve defining a new origin and a rotation angle or direction.

These coordinates (or the selected point) define the position of the origin of the positioning axis system (green) in the first sweep plane. The direction defines the X axis of the positioning axis system.

Position Profile : Parameters

Or

45 deg

You can rotate the positioning axis system

around the guide curve with

respect to initial axis system of the profile.

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Creating an Explicit-type Swept Surface (5/7)

In the Position profile mode you can display parameters to modify the position of the sweep profile on the guide curve defining a new origin and a rotation angle or direction.

You may want to invert the orientation of the X or Y axes of the positioning axis system.

You can select a point defining the origin of the axis system linked to the profile.

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Creating an Explicit-type Swept Surface (6/7)

You can select a second guide curve to define the sweep.

Second Guide Curve and Anchor Points

• If you check the Profile extremities

inverted option, the profile extremities connected to the guides are inverted.

• If you check the Vertical orientation

inverted option, the vertical orientation of the profile is inverted.

If no spine is selected, the first guide curve is the spine :

You can create a spine if you want to obtain a more regular surface :

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Creating an Explicit-type Swept Surface (7/7)

Second Guide Curve and Anchor Points

You also can use Anchor Points to position the profile on the guide curves.

Anchor points Profile Guide curves

While creating the swept surface, the anchor points are remaining on the guide curves all the sweep long.

So, the profile is positioned regarding to the initial geometrical conditions between the profile and the anchor points.

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You will learn how to create swept surfaces using Linear Profiles

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1

2 Creating a Line-type Swept Surface : Two Limits

Line type :

3

Confirm surface creation Click on the Line icon, then select the Two limits subtype and the two guide curves.

If no spine is selected the first guide curve is used as spine. Subtype : Two limits

Length 1 Length 2 Guide curve 1 Guide curve 2 You can select the

second guide curve as middle curve instead of entering length values (same as Limit and middle subtype)

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1

2 Creating a Line-type Swept Surface : Reference Surface

Line type :

3

Click on the Line icon, then select the With reference surface subtype, the guide curve and the reference surface. Key in an angle value and define the length of the surface.

If no spine is selected the first guide curve is used as spine.

Subtype : With reference surface

Angle between the sweep and the reference surface. Length 2 Length 1 Guide curve 1 Reference surface Angle

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1

2 Creating a Line-type Swept Surface : Tangency Surface

Line type :

3

Confirm surface creation

Click on the Line icon, then select the With tangent surface subtype, the guide curve and the tangency surface.

If no spine is selected the first guide curve is used as spine.

Subtype : With tangency surface

Tangency surface Guide curve 1

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You will learn how to create swept surfaces using Circular Profiles

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1

2 Creating a Circle-type Swept Surface : Two Guides and Radius

Circle type :

3

Confirm surface creation Click on the Circle icon, then select the Two guides and radius subtype, the two guide curves and the radius.

If no spine is selected the first guide curve is used as spine.

Subtype : Two guides and radius

Radius

In case of several solutions you can check them all and then select one of them (green color = active solution)

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1

2 Creating a Circle-type Swept Surface : Center and Radius

Circle type :

3

Confirm surface creation

Click on the Circle icon, then select the Center and radius subtype, a center curve and a radius.

If no spine is selected the center curve is used as spine.

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Copyright DASSAULT SYSTEMES 2002 70 Click on the Circle icon, then select the one guide and tangency surface as subtype. Select the guide curve, the tangency surface, and key in a radius sufficient to link the guide curve and the tangency surface.

Creating a Circle-type Swept Surface : One Guide and Tangency

Surface

Circle type : Subtype : One Guide and Tangency Surface

1

2

In case of several solutions you can check them all and then select one of them (orange color = active solution)

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You will learn how to create swept surfaces using Conical Profiles

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1

2 Creating a Conical-type Swept Surface : Two Guide Curves

Conical type :

3

Confirm surface creation Click on the Conic icon, then select Two guide curves and their tangency supports.

Define an angle between the swept surface and the tangency surface

Subtype : Two Guide curves

Set the parameter value (ranges from 0 to 1) indicating the sweep proximity to the spine.

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1

2 Creating a Conical-type Swept Surface : Five Guide Curves

Conical type :

3

Confirm surface creation Click on the Conic icon, then select Four guide curves and a tangency support.

You can specify a Spine curve. The default spine is always the first guide curve.

Subtype : Five Guide curves

Five Guide Curves

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You will learn what is an Adaptative Swept Surface and how create it

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What is an Adaptative Swept Surface.

You can modify the constraints defined in the original sketch independently for each section.

Sketch By giving some points, _you _will _define automatically

intermediate sections on the spine.

This particular sweep uses a Sketch as Implicit profile along a Guiding Curve. The guiding curve is used as the default spine.

Guiding Curve

The Sketch has been designed in context directly from the dialog box and represent a connex profile

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What are the differences with the Classic Sweep.

In an adaptative sweep, the surface inherits of the sketch constraints.

In the Explicit sweep the surface does not inherit of the constraints defined in the sketch.

The Implicit sweep is always defined from a sketch. This leads to build a surface that inherits of the sketch constraints scheme on the whole surface. Besides you can create on the fly intermediate sections along the guiding curve and modify the constraints independently in each section.

If we analyse the connections between the surfaces, there is a few acceptable tangency discontinuity areas.

If we analyse the connections between the surfaces, there are important tangency discontinuities.

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1 Creating an Adaptative Swept Surface (1/3)

2

Select the Adaptative Sweep icon. Select the Guide Curve and the Sketch to be swept.

3

Select points or vertices on predefined the guide curve to add intermediate sections.

Sketch

Guiding Curve

Intermediate sections

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4 Creating an Adaptative Swept Surface (2/3)

Under the Parameters tab, you can modify the constraints defined in the original sketch for each section independently

75 mm radius

22 mm radius Use this icon to

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5 Creating an Adaptative Swept Surface (3/3)

Under the Moving Frame tab, you can replace the spine (the default one is the guiding curve).

Click OK to confirm the surface creation

6

The Discretization scroll bar allows you to define the precision of the surface. The step value define the number of virtual intermediate sections used to create the surface.

Result with a discretization step = 1.00 Result with a discretization step = 0.50

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Additional Information on Adaptative Sweep (1/2)

If you want to create an adaptative swept surface

which lays on other surfaces, you will create your sketch in context because you want to put some associative constraints with the existing geometry.

Here we want that the sketch keeps its tangency with the surfaces (the intersection between the surface and the sketch plane) in each section of the sweep.

In many cases, you will meet some difficulties to build associative elements from existing geometry.

To avoid this problem, it is better to build its sketch directly from the Adaptative sweep dialog box.

Open a contextual menu in the Sketch field then choose Edit Sketch.

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Additional Information on Adaptative Sweep (2/2)

The Sketch Creation for Adaptative Sweep dialog box is displayed.

You just have to follow the instructions of the prompt bar.

Click on OK, the sketch is automatically defined with the construction elements.

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In this lesson, you will review WFS tools to transform, to split, and to

trim 3D geometrical elements. You will also see additional, powerful

tools in GSD for Filleting, Extrapolating, Healing, and inverting the

orientation of Surfaces.

Review of WFS Operations

Joining Surfaces

Healing Surfaces

Smoothing Curves

Extracting Elements

Federating Elements

Creating Fillets

Inverting Orientation

Creating Laws

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WFS Operations versus GSD Operations

Wireframe & Surface Design and Generative Shape Design are two workbenches which have many common functionalities.

Within GSD you will discover new functionalities that are not in WFS and also advanced capabilities in some functions that exist in both workbenches.

Functionalities specific to the Generative Shape Design workbench.

WFS

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Review of WFS Operations

You can review the tools covered in the Wireframe & Surface Design Course which

are also included in the Generative Shape Design Workbench.

Restoring Surfaces Disassembling Surfaces Splitting Elements Trimming Elements Transforming Elements

-

Translating an Element

-

Rotating an Element

-

Applying a Symmetry to an Element

-

Scaling an Element

-

Creating an Affinity

-

Performing an Axis-to-Axis transformation

Extrapolating Elements Creating Near Elements Creating Patterns

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You will learn how to join wireframe or surface elements

Joining Elements

Element 1

Element 2

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What about joined elements ?

You can create joined elements from:

- adjacent curves - adjacent surfaces

You can join elements to use two or more elements as a single element in a further operation.

Why Joining Elements ?

Four adjacent surfaces. Join result Join result Two adjacent splines.

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Let ’s see now the way to join elements ...

How to Join Elements…

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1

2

Select one by one the elements to be joined together.

Joining Elements (1/2)

3

Click OK to confirm join operation.

To modify the join definition you can edit it and remove elements or replace an element by another. This option checks

the connexity

between the elements in the resulting join.

CATIA will:

- reduce the number of resulting elements - ignore the elements that do not allow the join to be created. You can define a merging distance, i.e. the maximum distance below which two elements are considered as only one element.

Element 1

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Joining Elements (2/2)

While joining elements you can exclude some sub-element from the joined surface.

Face to be removed You can also select

sub-elements to exclude from the joined surfaces.

You can create another join surface with the excluded sub-elements.

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While joining surfaces, you can specify an angle tolerance.

If the angle value on the edge between two elements is greater than the Angle Tolerance value, the elements are not joined

Additional Information on Joining

Select the elements to be joined. The tangency

discontinuity between these surfaces is 6deg :

Activate the new option Angle Tolerance.

CATIA refuses to create the join surface because the tangency discontinuity between the surfaces is greater than the specified angle tolerance:

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Healing Surfaces

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Why Healing?

While Join is a topological integration of surfaces into one logical surface, HEALING will mathematically deform the shape of surfaces at boundary areas so they smoothly blend into one another.

When physical parts are manufactured from CAD models, the machining is guided by the exact representation of the individual surfaces. Hence, Healing is important to ensure that each one of these surfaces transitions smoothly between one another.

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1

2 Healing Surfaces (1/3)

3

Choose if you want to heal _{the point discontinuities or}

the tangency discontinuities.

Select the Join where you know there is a gap that you would like to Heal. You can also select directly the surfaces to heal.

(94)

Healing Surfaces (2/3) : Parameters

The objective of the parameters is to choose the discontinuities you want to heal or not :

4

Key in parameters :

Note : a quick violation analysis can help to choose these parameters :

Healed Not healed

Merging distance

Healed Not healed

Tangency angle

Not healed Healed

Distance Objective

Not healed Healed

Tangency Objective

Gap value

Tangency discontinuity value These parameters are thresholds that allows you to:

- define the discontinuities to be healed (Merging distance and Tangency angle).

- define the discontinuities you consider it is not

necessary to heal (Distance Objective and Tangency Objective).

(95)

Healing Surfaces (3/3)

5

Click OK to confirm the

healed surface creation.

(96)

Smoothing Curves

(97)

We want to create a Line-type sweep from this curve using the plane as reference surface.

Why Smoothing Curves

Sometimes when you want create a sweep for instance, CATIA answers you that the profile curve is not continue in tangency and that it could not build the geometry as you whish. The Smoothing Curve function allows you to clean these curves in distance and tangency.

We need to smooth the curve before generating the sweep.

We can see the discontinuity points and their values to correct the curve.

Using the smoothed curve, we can create the swept surface.

(98)

1

2

Select the curve to be smoothed.

Smoothing Curves (1/2)

3

Using the displayed values, set the _{tangency and curvature thresholds}

up to the value you want to repair.

Select the Smoothing Curve icon.

A discontinuity analysis is displayed :

- In area : discontinuity

type and value before smoothing.

- Out area : discontinuity

status after smoothing.

(99)

Smoothing Curves (2/2)

Click OK to create the smoothed curve : it will lie on the surface.

1

2

Select the curve to smooth.

3

Define the smooth parameters.

4

Select the support surface (the curve

to smooth must lie on this surface).

5

(100)

Additional Information on Smooth Curve(1/2)

Meaning of the boxes colour:

The status of the discontinuities is displayed using a colour code.

A red boxred box means that the discontinuity has not been corrected.

Reason : the discontinuity is not within the specified threshold.

A yellow boxyellow box means that the discontinuity has been partially corrected.

Reason : the discontinuity in tangency is within the tangency threshold, but the curvature discontinuity is not within the curvature threshold.

A green boxgreen box means that the discontinuity has been completely corrected.

Reason : both tangency and curvature discontinuity are within the curvature and tangency threshold.

(101)

Additional Information on Smooth Curve (2/2)

You can choose to visualize only the non-corrected discontinuities :

You can choose to visualize the discontinuities interactively, placing the mouse on the discontinuity to make the text box appear :

You can also display the information sequentially :

The total number of discontinuities is displayed.

(102)

You will learn how to extract edges and faces from a surface.

Extracting Elements

Edge extraction

Face extraction

(103)

1

2

3

Select a surface edge and choose the propagation type.

Click OK to confirm edge extraction.

Extracting an Edge from a Surface

Selected edge

According to the selected propagation type you get :

1- No propagation 2- Tangent continuity 3- Point continuity

Here there is an ambiguity about the propagation side you are prompted to select a support face. In this case, the dialog box dynamically updates and the Support field is added.

You can extract one or several edges of a surface which can be either boundaries or limiting edges of faces. You cannot define limit points.

Selected support face

(104)

1

2

3

Select a face and choose the propagation type.

Click OK to confirm face extraction.

Extracting a Face from a Surface

You can extract one or several faces of a surface with or without propagation.

The complementary mode :

Switching on this button, you can de-select the elements to extract, and select the non-selected elements :

(105)

You will learn how to federate elements while joining surfaces

and extracting faces

(106)

Why federate ? (1/2)

1- Surfaces are made of several faces.

Elements created from a surface are in fact created from its faces.

2- A modification of the part geometry may lead to a change of the supporting face.

The pad has been created with the option “Up to surface”, using the blue surface.

A fillet have been added to the top edge of this pad.

This edge depends on a face of the blue surface.

The sketch supporting the pad have been modified so that the filleted edge does not lie anymore on the same face

(107)

Why federate ? (2/2)

3- This change can lead to an update error because the elements created from these faces are no longer recognized.

4- Federating the faces of the surfaces, this kind of update error does not occur anymore.

During the update of the part, an update error occurred : the filleted edge is not recognized :

To solve the problem, you just have to federate the faces of the blue surface. Then the part is updated without any problem :

(108)

Let’s see now how to federate ...

How to Federate Elements

(109)

Click OK to create the federated joined surface.

1

2

Select one by one the elements to be joined together.

Federating Elements while Joining Surfaces

3

Expand the new “Federation” panel _{in the join dialog box.}

4

Select one face of the join surface

and choose a propagation type.

5

(110)

Copyright DASSAULT SYSTEMES 2002 110 Click OK to create the federated

extracted surface.

1

2

Select one face of the solid.

Federating Elements while Extracting Faces

3

Choose a propagation type.

4

Activate the federation switch.

5

Extracting faces from a solid, you have the possibility to federate the faces of the resulting surface

(111)

Creating Fillets

Filleting is an operation that is used to smoothly connect surfaces.

You will learn how to create Shape, Edge, Variable, Face-To-Face, and

Tri-Tangent Fillets

(112)

Why Fillets?

Fillets were originally used in industry to remove sharp edges on parts.

More and more, people having been using Fillets as a general modelling tool for surface creation.

(113)

1

2

Select the Shape Fillet Icon

Creating a Shape Fillet (1/3)

5

Choose one of the Extremities conditions (Switch between the four types - and Apply - to see the difference)

3

Click OK to confirm. The Shape Fillet is added to the specification tree

Select two surfaces and put in the required radius value. Make sure the red arrows point towards the concave side of the fillet.

4

Decide which supporting surface you want to trim.

(114)

Creating a Shape Fillet (2/3) : Extremity Type

Here are the different types of extremities

(115)

Creating a Shape Fillet (3/3) : Trimming the supports

Four combinations are possible :

No support are trimmed Both support are trimmed

The second support is left unchanged.

(116)

1

2

Select the Edge Fillet Icon

Creating an Edge Fillet (1/2)

Select one or more internal edges of a surface

Use these command to provide a transitional surface along a sharp internal edge of a surface

You can control the Extremities of the Fillet the same way as for the Shape Fillet

3

Enter the Radius value.

You can also fillet an entire face

(117)

Creating an Edge Fillet (2/2)

Choose a Propagation type :

4

Click OK to confirm. The Edge Fillet is added to the specification tree 5

If Minimal, only the selected edges will be filleted.

(118)

1

2

Select the Variable Fillet Icon

Creating a Variable Fillet (1/3)

3

Select one or more internal edges of a surface

4

You can specify a Zero radius value at limit points of a Variable Fillet

Double-Click on any of the shown radius values to change it

Select inside this box then select anywhere along the edge to put in an additional radius value along the edge. (You can also create a point on the edge and select this point if accuracy is required)

In this type of fillet the radius varies at selected points along a selected edge

You can control the Extremities of the Fillet the same way as for the Shape Fillet and the Propagation type the same way as for the Edge Fillet

(119)

Creating a Variable Fillet (2/3)

Choose a radius variation type : Cubic (function ax3_+bx2_+cx+d)

Click OK to confirm. The Variable Fillet is added to the specification tree

6 5

(120)

Creating a Variable Fillet (3/3)

Edge to be filleted

You have the capability to create a variable fillet with the fillet sections keeping a constant direction in accordance with a spine

The fillet sections are

perpendicular to filleted edge

The fillet sections are perpendicular to the Spine Spine

(121)

1

2

Select the Face-To-Face Fillet Icon

Creating a Face-To-Face Fillet

3

Click OK to confirm. The Face-To-Face Fillet is added to the specification tree

Select the two faces (belonging to the same

surface) between which you want to create the Face-To-Face Fillet

The shape of the Face-To-Face Fillet is basically generated by lying a Cylinder with a specific radius into the gap between two faces. If the radius is too small, the Cylinder will not be able to touch both faces at once. If the radius is two big, we will not be able to achieve a Cylinder tangent to the faces.

Put in the desired radius

4

Use the Face-Face fillet command when there is no intersection between the faces or when there are more than two sharp edges between the faces.

You can control the Extremities of the Fillet the same way as for the Shape Fillet

(122)

1

2

Select the Tri-Tangent Fillet Icon

Creating a Tri-Tangent Fillet

3

Click OK to confirm. The Tri-Tangent Fillet is added to the specification tree. Select the two faces you

want to keep

The Tri-Tangent Fillet is a variable radius Fillet tangent to all three faces selected.

Select the face to be removed.

4

The creation of tri-tangent fillets involves the removal of one of the three selected faces.

The three faces must belonging to the same surface.

(123)

Additional Information on Fillet : Hold Curve and Spine

This option concerns with all type of fillet : we will focus on the shape fillet creation.

Creating Fillets, you can now choose a curve sketched on one of the support to be connected to control the radius variation. Spine Curve

Hold Curve

Select a hold curve lying on one support to drive the fillet radius, And a spine curve.

Note : the result is a variable radius fillet whose radius is driven by the hold curve.

(124)

Additional Information on Fillet : Limiting Elements

This option concerns the edge, the variable radius, the face-face and the tri-tangent fillets.

While creating one of these fillets, you can limit it by selecting an element (plane or surface) that intersects it completely :

Edge to fillet

Limiting element

(125)

Additional Information on Fillet : Trim ribbon

This option concerns the edge and the variable radius fillets.

In some case, fillets may be overlapping. The Trim ribbons option lets you solve this by trimming the fillets where they overlap.

Overlapping fillets

(126)

Additional Information on Fillet : Rolling Edge (1/2)

This option concerns the edge and the variable radius fillets.

In some case, you may need to indicate that an edge should not be filleted, if a radius is too large for instance.

Click on the more button to expand the dialog box, then select the edge you wish to keep.

catia whole

Generative Shape

Design

CATIA Training

Foils

Course Presentation

Objectives of the course

This course covers tools for surface design included in the Generative Shape Design

Workbench that are not present in the Wireframe and Surface Design Workbench. At the

end of the course, the student will be able to model complex fillets and analyze surface

quality.

Targeted audience

Mechanical Designers

Prerequisites

Table of Contents

 Introduction to Generative Shape Design

p.6

 Creating Wireframe Geometry

p.12

Creating an Extremum

p.13

Creating a Polar Extremum

p.21

Creating a Reflect Line Methodology

p.29

Creating a Spine

p.39

Creating a Parallel Curve onto a Support within GSD

p.

Extracting Multiple Edges from a Sketch

p.

Tools for Wireframe Geometry Creation

p.

 Creating Surfaces

p.67

Creating Swept Surfaces

p.68

Table of Contents

1. Performing Operations

p.67

Joining Elements

p.

Healing Elements

p.

Smoothing Curves

p.

Extracting Elements

p.

Federating Elements

p.

Creating Fillets

p.

Inverting Orientation

p.

Creating Laws

p.

Using Analysis Tools

p.

Managing Features and Open Bodies

p.

Hybrid Design

(Working with Hybrid Parts)

p.

Generative Shape Design Workbench

Generative Shape Design Interface

Generative Shape Design Terminology

In this lesson you will see V5 Generative Shape Design user interface

and basic functions

Accessing the Workbench

Open

Body

Terminology

General Process

Creating Wireframe Geometry

In this lesson, you will learn how to create all types of Wireframe

elements.

WFS Wireframe versus GSD Wireframe

Review of WFS Wireframe Geometry

You can review the tools covered in the Wireframe & Surface Design Course which

are also included in the Generative Shape Design Workbench.