• The design process and the role of CAD-Ch#1
• Design process, role of modelling and communication,
design models, concurrent engineering, modelling using
CAD, CAD system architecture
• Defining the model-Ch#2
• Techniques for geometric modelling-Ch#3
• Elements of Interactive computer graphics-Ch#4
• Entity manipulation and data storage-Ch#5
• Standards for CAD-Ch#6
• Industrial Robotics
5. Introduction to CAD/CAM
• Airbus380 The world's largest passenger airliner,
$0.5B, 853 passenger Max, 16K Km range..
• 1990 Project announcement
• 1994 Product announcement
• 2000 Restructured after recession ‘97~2k
• 2001 Design completed
• 2002 Component production
• 2005 Test flight
• September 2006, the first full passenger-carrying
• October 2007 delivered to Singapore Airlines
7. Introduction to CAD/CAM
• Major structural sections of the A380 are built in France,
Germany, Spain, and the United Kingdom
• Delays attributed to the 530 km (330 mi) of wiring,
complexity of the cabin wiring (98,000 wires and 40,000
• Concurrent design and production,
• High degree of customisation for each airline, and
• failures of configuration management and change control.
The German and Spanish Airbus facilities continued to use
CATIA version 4, while British and French sites migrated to
version 5. This caused overall configuration management
• Lost revenue $5B and penalties from airliners
8. CAD/CAM Introduction
• We see the touch of engineers everywhere-building,
equipments, vehicles, rails, etc
• Now many products are very complex, need large
team to collaborate the product development and
manufacturing. Increased performance, quality and
• Need to shorten time and cost due to competition.
• So need computer help i.e. CAD
9. Process for bringing a product to
Design analyst-Analysis and Simulation
Development/research engineers-carry expt. work on
prototypes and refine design
Process planner-identify process and operations required
Production planner and controller-schedule of production
10. Models of Design Process
Formal description of the stages or elements
of design process. Though there are
variation in terminology and in detail, they
agreed a step-by stem manner
• Phal and Beitz Model
• Oshuga Model
13. Role of Modelling and communication
Design model and models of design process?
Design is abstract until manufactured.
So we need models to evaluate, manipulate and
refine. Models are used for recording and
manipulating ideas and provide a basis for
evaluation of the design.
Models have a major role in the communication of
design between participants in the process
14. Types of design
• Varity of representation is required from
preliminary layout to complete design.
• Models depend on what design property to be
modelled, who or what is target or receiver
• Model the function of a design, structure, form,
shape, surface condition, dimension, material etc.
• It may be mathematical model
16. Applications of design Models
• Evaluating Action-to
assess the properties and
merits of design
• Generative Action-
Generate information from
model for use downstream
of the design process,
usually in order to
progress its manufacture
• In both case extraction of
information from model is
17. Applications of design Models
• Design Analyst do-
• A visual assessment
• Mass of the
• Evaluation of stresses
• Manufacturing engs.
• Extract info for tooling
• For control of
18. Traditional design process and
• Traditional: design descriptions are produced in the form of
engineering drawing..etc. by design department, then design is
sent for analytical evaluation, and for preparation of plans and
instructions for manufacture.
• If manufacturing specialist and design analyst find issues, they
send it back to design department which is than reissue the
design. In aerospace manuf. Avg. drawing change is 4.5 times.
• Designer concentrate on functional aspects at the expense of
ease of manufacturing, maintainability etc.
• Concurrent Engineering aims to overcome all these issues by
bringing together a design team with appropriate combination of
specialist expertise. Where CE is not suitable
19. Concurrent Engineering
• Both Phal & Beitz Model and Ohsuga Model are traditional
view (sequential models)-sequence of design stages,
followed by manufacturing.
• However pressure to reduce product design and
development time-scales leading companies to conduct
design, development, analysis and the preparation of
manufacturing information in parallel.
• This concept is know as Concurrent Engineering.
• Mainly used by those companies which have established
products and where ew models are required at regular
21. CAD in Modelling
• Design progressively refined in the abstract, until it is
completely defined for manufacture
• A series of models of various aspects of the design are
• Sequencially/Concurrently others extract info from these
models and forms new models to assist them
• Parallally developed
• Models of functional and other custormer requirement s for the
• Models of constraints on design, imposed by available mat.,
manuf. Process etc.
• Models of loads imposed on design
• Models to evaluate performance of the design..stress, thermal etc..
23. CAD System Architecture
• CAD System consists of –Hardware, Software, data
and human knowledge and activities
• Software-comprises of different elements or process
data stored in the database in different ways. These
• Model definition
• Model manipulation
• Picture generation
• User interaction
• Database management
• Utilities-color to display
1. Take a sheet of paper, write your student ID, name,
sketch different components of the pen you are using.
Submit the paper. Draw 3D models of each
components(1:1 scale), assemble them and submit
2. Make a list of top 10 CAD Software(5-open source/free
and 5-non-opensource/commercial) and compare their
3. 3D models of Assignment 1 must be created by at least
1 Open source/Free and 1 non-open
source/commercial CAD software.