CAD

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CHAPTER 1(a)
Introduction to CAD, CAM and CAE
MEC435

COMPUTER-AIDED DESIGN
OBJECTIVES
• Understand the various spheres of manufacturing activity
where computers are used
• What is meant by product cycle with the differences
between the conventional and computer based
manufacturing systems
• Definitions of various computer based applications
• Computer Aided Design and its applications
• Various types of manufacturing organizations
• Computer Aided Manufacturing and its application
• Meaning of Computer Integrated Manufacturing
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COMPUTER AIDED
ENVIRONMENT
• Nowadays, computers become very crucial to daily life –
aids users in daily task/work.
• CAD/CAM are widely used in engineering practice:
– Drafting
– Design
– Simulation
– Analysis
– Manufacturing
COMPUTERS IN INDUSTRIAL
MANUFACTURING
• The role of computer in manufacturing
may be broadly classified into two
groups:
1. Computer monitoring and control of the
manufacturing process.
2. Manufacturing support applications, which
deal essentially with the preparations for
actual manufacturing and postmanufacture
operations.
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COMPUTER AIDED
PROCESSES
• CAD - computer aided design.
• CADD - computer aided design and drafting.
• CAE - computer aided engineering.
• CAM - computer aided manufacturing.
• CAPP - computer aided process planning.
• CATD - computer aided tool design.
• CAP - computer aided planning.
CAD/CAM Major Areas
1. Geometric modeling
2. Computer graphics
3. Design application
4. Manufacturing Applications
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COMPUTER AIDED
ENVIRONMENT IN
MANUFACTURING
COMPUTER AIDED DESIGN
• Design is an activity which needs to be
well organized and take into account all
influences that are likely to be
responsible for the success of the
product under development.
• The complexity of the design process increases
with the number and diversity of components
present in the final part.
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PRODUCT ENGINEERING
• Product functions
• Product Specifications
• Conceptual design
• Ergonomics and Aesthetics
• Standards
• Detailed Design
• Prototype development
• Testing
• Simulation
• Analysis
• Strength
• Kinematics
• Dynamics
• Heat
• Flow
• Design for Manufacture
• Design for Assembly
• Drafting

ADVANTAGES OF CAD
• Is faster and more accurate than conventional
methods.
• A very easy task.
• Editing
• Never have to repeat the design or drawing of
any component.
• Accurately calculate the various geometric
properties
• Use of standard components (part libraries)
• 3D (3 dimensional) visualization capabilities
COMPUTER AIDED
MANUFACTURING
1. Mass production ─ large lots e.g.
automobiles
2. Batch production ─ medium lot sizes e.g.
industrial machines, aircrafts, etc.
3. Job shop production ─ small lots or one off,
e.g. proto-types, aircrafts, etc.
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MANUFACTURING
ENGINEERING
• Process planning
• Process sheets
• Route sheets
• Tooling
• Cutting tools
• Jigs and Fixtures
• Dies and Moulds
• Manufacturing Information
Generation
• CNC Part programs
• Robot Programs
• Inspection (CMM) programs
• Production Organization
• Bill of Materials
• Material Requirement
Planning
• Production Planning
• Shop Floor Control
• Plant Simulation
• Marketing and Distribution
• Packaging
• Distribution
• Marketing
ADVANTAGES OF CAM
• Greater design freedom
• Increased productivity
• Greater operating flexibility
• Shorter lead time
• Improved reliability
• Reduced maintenance
• Reduced scrap and rework
• Better management control
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COMPUTER AIDED
ENGINEERING
• The use of information technology for supporting
engineers in tasks such as analysis, simulation,
design, manufacture, planning, diagnosis and
repair.
• CAE tools are being used, for example, to
analyze the robustness and performance of
components and assemblies including
simulation, validation and optimization of
products and manufacturing tools.
AREAS OF CAE
• Stress analysis on components and assemblies
using FEA (Finite Element Analysis)
• Thermal and fluid flow analysis - Computational
fluid dynamics (CFD)
• Kinematics
• Mechanical event simulation (MES)
• Analysis tools for process simulation for
operations such as casting, molding, and die
press forming.
• Optimization of the product or process.
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ADVANTAGES OF CAE
• Reduce product development cost and time
• Precise analysis and simulations
• Early prediction of results
• Design verification through simulation without
having to use physical prototype testing
• Minimize the time for optimizing products
• Parallel task can be done along the design
stages