— In 1960's
• mechanism design satisfying
several geometric constraints
• design parameter optimization
• simple 2-D graphics
— In 1970's
• wireframe modeling
• free-form surface modeling –
mainframe computers
• solid modeling
— Early 1980's
• CAD/CAM integration
• mechanical feature recognition
from a CAD database
— Middle 1980's
• feature-based CAD system –
mini and micro computers,
• parametric
design
-- PC's & Turnkey systems
(Pro/ENGINEER Products)
— Late 1980's
• design for manufacturing
• design for automated assembly
— 1990's
• concurrent engineering design
• integrated design, analysis and
optimization
• virtual-prototyping –
workstations and high-end PC's
Combining the precision
of electronic graphics and the mathematical processing power of a digital
computer.
• Electronic drafting using a
Computer-Aided Drafting system
• Basics of computer graphics
• Geometric modeling
• Design modeling using an
advanced CAD/CAE/CAM system
• Finite element analysis
• Engineering optimization
(optional)
• Virtual (Soft) prototyping
(optional)
(a)
Learning the fundamental
theory of computer graphics and geometric modeling
q
Geometry
transformation, curve and surface generation
q
Solid modeling and
data exchange
q
Use of Matlab to
generate an engineering drawing
Emphasis on the understanding of basic
techniques of computer graphics and geometric modeling
(b)
Introducing the
recent advance in Computer-Aided Design and Modeling using a representative
commercial CAD system – Pro/Engineer
q
Feature-based design and parametric
modeling
q
Part and assembly
modeling
Advanced applications of
CAD
(c) Learning
basics of finite element analysis (FEA) and the state-of-the-art analysis tool
– Pro/Mechanica
q
Concepts of finite element analysis
q
Basic elements and applications
q
Use of FEA in industrial design
Engineering analysis integrated with CAD
and emphasis on problem solving
Examining the nature and scope of CAD by going
through the diverse applications of CAD systems (slides in lecture)
Figure 1
Computer-Aided Design,
Analysis and Manufacturing.
—
The
Primary Capability – Generating Perfect Scale Drawings
• accurate
scale line drawings in 2D and 3D
• drawings
of 3D sculptured surfaces
• solid
model of 3D objects
This
capability sets CAD apart from other uses of computer
—
Many
Diverse Capabilities
• artistic
creation of shaded 3D shapes and patterns
• automatic
generation of design databases
• facilitating
engineering analysis
• providing
input to, monitoring, simulating and controlling manufacturing activities.
Specifically, the functions of Computer-Aided Geometry
Design include:
—
Specification
of Design Geometry
• Computer-aided
drafting (interactive graphics programming and user interface)
• Customizing
CAD systems
—
Geometric
Modeling and Representation
• Computer
model of part and assembly design (data structure and data base design)
—
Visualization
• Architecture
view of a design
• Computer
games and education programs
—
Generation
of Manufacturing Oriented Database
• Feature-based
design
• Parametric
design
—
Animation
and Simulation
• Mechanism
• CNC
machining
• Robot
trajectory
• Automobile
crash
—
Tolerance
Representation and Automated Tolerancing
• Dimension
relation analysis
• Tolerance
analysis
• Tolerance
synthesis
—
Automobile
crash Pre- and Post-interfaces to Finite Element Analysis Programs
• Automated
mesh generation
• Graphical
display of stress distribution
—
Design
Automation
• Design
optimization
• Design
for manufacturing
• Design
for automated assembly
• Concurrent
engineering design
—
Virtual
(or Soft) Prototyping
—
Reverse
Engineering
a) Graphical
and Topological Information
• Part
geometry
• Assembly
relations
b) Textual
Information
• Dimensions
• Tolerances
(dimensional & geometric)
• Materials
• Surface
finishes
Current
Approach:
The geographical information is
represented using low level graphical elements such as points, lines, arcs,
etc. The textual information is represented as texts, notes and symbols
attached to a drawing.
The
Ideal Approach:
To represent part geometry using
high-level feature primitives such as holes, slots, pockets, etc. (consistent
to the engineering practice), and to represent dimensions, tolerances, surface
finishes, etc. as meaningful design entities.
a) Representing
geometric shape
• Computer
graphics (2D)
• Geometric
modeling (3D)
b) Interactive
Graphical Programming
• Programming
on different platforms
• Graphical
User Interface
c) Manipulating
and storing design data
• Data
structure design
• Database
system
d) Generating
feasible designs (automatically)
• Knowledge
reasoning
• Knowledge-based
system
• Fuzzy
logic
• Artificial
neural networks
e) Evaluating
design alternatives and identifying the optimal design solution
• numerical
optimization
• finite
element method
• cost
modeling and analysis
