youssefi course notes ii ptii

8/3/2019 Youssefi Course Notes II PtII

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Unigraphics

An Interactive CAD/CAM/CAE System

??The CAD functions automate the normal engineering, design, anddrafting

??The CAM functions provide NC (Numeric Control) programming

for modern machine tools

??The CAE functions provide the analyses of the design model to

check if the part can satisfy design requirements in mechanical,thermal, or dynamic aspects

??Unigraphics functions are divided into applications


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Unigraphics Coordinate systems

??Absolute Coordinate System (ABS)

Defines 0,0,0 (in X, Y, and Z) in model space and it isfixed, used as a general reference for large assemblies,

not seen on the screen.

??Work Coordinate System (WCS)

A mobile coordinate system that may be moved around

to facilitate the construction of objects. The WCS is

identified by a letter C next to each of the axes (XC,YC, and ZC).

??Change the Origin

??Rotate the system (changes orientation, not location)

??Orient the WCS (rotational and location change)

Most operations do not require you to manipulate the WCS

?? Featured Coordinate System

Created by the Unigraphics and stored with the

feature, called by UG during editing, it is transparent.


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Unigraphics Layers

?? Used to organize modeling file

?? There are 256 layers available in every single partfile.

?? A layer is a single piece of transparent film withinformation on it.

?? At any given time, you can only create objects on asingle layer, the working layer.

?? Layers can be made Selectable (you can pick and

work with the objects on a layer).

?? Layers can be made Visible (you can see, but not pick

and work with the items on that layer).


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Unigraphics Primitives

Primitive features are base features to which other features are

added. UG uses five primitives:Blocks, Cylinders, Cones, Spheres,

and Tubes.

Procedure to create a primitive

?? Select the type of primitive (Insert? Form Feature)

?? Choose the creation method.

?? Enter the creation parameter values.

?? Use Boolean operation if other solid objects exist.

Block :

1. Define the length of each edge and a corner point

2. Define the block height and two diagonal points of the block

base

3. Define two 3D diagonal points representing opposite corners ofthe block

Cylinder:

1. Diameter and Height; define the cylinder direction vector, enterdiameter and height values, define the cylinder origin.

2. Height and Arc; enter the height value, select an arc, confirm

the cylinder axis direction.


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Unigraphics Form Features

Features that are added or subtracted from the base feature.These areHole, Boss, Pocket, Pad, Slot, and Groove.

The basic procedure to add a form feature to your part is:

1. Select thePlacement Face.

2. Select aHorizontal Reference if required.

3. Select Thru Face if required.

4. Enter values for the feature parameters.

5.Position the feature.


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Positioning Form Features

A feature or a sketch may have to be positioned relative existingsolid body geometry. This is done by creating positioningdimensions calleddimensional constraints.

There are nine dimension types.


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Unigraphics Operations on Edge and Face

Edge BlendModifies a solid body by rounding the selected edges.

??Fillet rounding of the inside corners??Round curving of the outside corners

ChamfersAllows you to bevel edges of a solid by defing the desired

chamfer dimensions.


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HollowThis feature allows you to hollow out or create a shell

around a single solid body based on specified thicknessvalues.

Three types of hollow operation:Face

BodyRegion


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Sketching

??A sketch is a set of two dimensional curves joined in a

string that when swept forms a solid body.

??Curves may be created free-hand with no exact size, orcreated exactly to size, or free-hand creation may be

changed to exact size at a later time.

??Curves are parametrically associated to each other and the

solid that is created by them.

??The exact size of the curves are controlled by addingconstraints which can be edited to change sizes.

??Ideal for creating unusual shapes.

??Sketches are able to capture the designers intent for the

part like no other technique.

??The sketch is the best tool for creating solids because offlexibility in shapes and the ability to edit.


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Sketching in UG

General procedure

??ChooseInsert ? Sketch

??Select Create sketch

??Choose the plane to sketch on

??Enter name for sketch

??Choose a Curve Construction option and draw

??If desired, constrain the curve

??If desired, position the curve

??Sweep the sketch into a solid body.


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Sketch Constraining Concepts

Constraining means to define exactly the physical size and

orientation of curves and to define its relationship to

other curves.

Applying a constraint to a sketch allows a designer tocapture the design intent.

??Dimensional Constraints

o Defines the size of a curve by a dimension, there are 8

dimensional constraints (Horizontal, Vertical, Angular, Diameter,

Parallel, )

o Dimensions may be edited to change the size

??Geometric Constraints

o Defines the geometric characteristic of a curve or therelationship between 2 or more curves., there are 20 geometric

constraints (Concentric, Collinear, Equal length, Equal radius,

Parallel, Perpendicular, .)

o They may be added or removed to make changes

Sketches do not have to be constraints to build parts


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Extrude and Revolve

Extrude allows a solid body to be created by sweeping planargeometry in a linear direction over a specified distance.

Revolve revolves a planar geometry around a radius andthrough an angle

Revolved feature Extruded feature


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Revolved feature

??Sketch a 2D profile.

??Revolve the sketch around the centerline.

youssefi course notes ii ptii

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