In the name of ALLAH, the Beneficent, the Merciful'

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In the name of ALLAH, the Beneficent, the
Merciful.
Read! In the name of thy Lord who Creates
Creates man from the clot of blood
Read! And your Lord is the most Generous
Who Teaches by the pen
Teaches man that which he knew not.
( Al-Quran, The Clot, Verse 1-5)
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Design
Process of Conceiving or Inventing Ideas
TEACHES MAN THAT WHICH HE KNEW NOT.

• Heart of Engineering.
• Mechanical
• Civil
• Electrical
• Chemical
• Computer engineering

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COMPUTER
Logic Unit
CPU
Control Unit
Graphical Output
Output
Input
Graphical Input
Memory
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Computer-aided design (CAD) is the use of
computer systems to assist in the creation,
modification, analysis, or optimization of a
design.
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HISTORY AND BACKGROUND
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• Two-dimensional (2-D) drafting systems

1960s
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Wire Frame Models
Late 60s
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Wire Frame Models

• Name is given due to appearance
• Displays only edges
• Simple 2D principle with inclusion of Z-axis

Data Base Information -Vertices -Edges -Faces
Data Base Structure -Hierarchy -Array -Network
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Wire Frame Models

• Disadvantages
• Not able to fully define real objects
• (No volume and mass)
• Displays only edges of a model (No Surfaces)

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Surface Modeling
Early 70s
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Surface Modeling

• Developed for the Air-craft Ship building
  Industry
• Surfaces are used to construct a model

• Surfaces can be
• Planar
• Cylindrical
• Free form

Computer programming is done using mathematical
methods.
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Surface Modeling

• Surface models provide a more complete
  description of the object, but is still not as
  good as the solid model.

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Solid Modeling
Mid 70s
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Solid Modeling

• Real world Solid models can be made.
• Direct creation of 3-D geometry, i.e. sphere,
  cone
• 3-D Models are created by combination of simpler
  solids
• Boundary Representations

Different Boolean operation are used to combine
primitives. Intersection? and Union?
or Subtract/Difference? not
Simple solid objects are named as primitives
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Primitive Modeling - combine simple shapes
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Solid Modeling
Solid
B-Rep
CSG
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Revolving
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Extrude
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Assembly Modeling
Late 70s
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Assembly Modeling

• Solve the problem of proto-type actual component
  assembly
• Automotive and aerospace industries among the
• first to make extensive use of assembly
  modeling.

Computer Data base includes
Relationship Database

• Tolerances
• Fits

Instancing
Constraint
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Parametric Modeling
1980s
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Parametric Modeling
In a parametric model, each entity has parameters
associated with it. These parameters control the
various geometric properties of the entity. such
as the length, width, height,
General form of Parametric Equation XX(t) YY(t)
ZZ(t)
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Parametric Modeling
Parametric Modeling
Constraint-Based Modeling
Dimension-Driven Modeling
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Feature-based Modeling

• Feature-based modelers allow operations of
  creation
• to be associated with specific edges and faces
  such as
• holes,
• fillets,
• chamfers,
• bosses,
• pockets to be associated with specific edges and
  faces.

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Benefits of CAD

• Time Saving
• Accuracy
• Modifications can be made quickly
• Easy access to fonts, Text editing
• Advantage of color in CRT
• Simulations
• F.E.M
• Integration with CAM
• Creation of 3-D Models

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Simulation
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INTEGRATION OF CAD/CAM
CAD Program
CAM Program
CNC Program
DXF File
NC File
Integration with CAM
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Finite Element Modeling
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Finite Element Modeling
The finite element method (FEM), is based on the
idea of building a complicated object with
simple blocks.
Complicated object is divided into simple and
manageable blocks
Applications
Mechanical/Aerospace/Civil/Automobile
Engineering Structure analysis Heat
Transfer Electromagnetic
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Elements, Nodes, and Meshes
Nodes
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The Modeling Process
Physical Reality
Model of the Physical Reality
Good Predictor?
Mathematical (FEA) Model
Solution of the Mathematical (FEA) Model
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Defining the Six Principal Views
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AutodeskMECHANICAL DESKTOP
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Pull-down Menus
Contains the default AMD menus
Title Bar
Standard Toolbar
Name of Drawing, its format, Minimize Maximize
and close Box
Contains Standard buttons for operations
Browser Bar
Graphics Cursor
Locates points, draws and select objects
Graphics Window
Display Drawings
Command Line window
Display prompt messages used to enter a
command
Cursor Coordinate Display
Status Bar
Display cursor co-ordinates, Shows different
modes of current drawing
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ISOMETRIC PROJECTION An Isometric Projection is
constructed from 3 axes created by dividing a
circle into 3 equal angles of 120degrees
Revision
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Perspective Sketching
Perspective sketching has no parallel lines and
is therefore difficult to construct
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Work Planes

• Work Plane are required when
• A part face is not available as a sketch plane
  for sketching new features.
• An intermediate position is required to define
  other work planes
• (for example, at an angle to a face at an offset
  distance).