1/19/2009 1 Semester Dis08 ~ April 09 KJM 573 KJM 573 CAD CAM CAE CAD CAM CAE Introduction to CAD CAE CAM Introduction to CAD CAE CAM A design drawing for an engine. What is Computer-aided design (CAD) The use of computer technology to aid in the design of a product. Current packages range from 2D vector base drafting systems to 3D solid and surface modelers. Vector graphics (also called geometric modeling or object- oriented graphics) is the use of geometrical primitives such as points , lines , curves , and polygons , etc.. Origins and terminology CAD originally meant Computer-Aided Drafting because of its original use as a replacement for traditional drafting. Now, CAD usually means Computer Aided Design to reflect the fact that modern CAD tools do more than just drafting. CAD is sometimes translated as "computer-assisted"
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1/19/2009
1
Semester Dis08 ~ April 09
KJM 573 KJM 573
CAD CAM CAECAD CAM CAE
Introduction to CAD CAE CAM Introduction to CAD CAE CAM
A design drawing for an engine.
What is Computer-aided design (CAD)
The use of computer technology to aid in the
design of a product. Current packages range
from 2D vector base drafting systems to 3D
solid and surface modelers.
Vector graphics (also called geometric modeling or object-
oriented graphics) is the use of geometrical primitives such
as points, lines, curves, and polygons, etc..
Origins and terminology
CAD originally meant Computer-Aided Drafting because of its original use as a replacement for traditional drafting.
Now, CAD usually means Computer Aided Design to reflect the fact that modern CAD tools do more than just drafting.
CAD is sometimes translated as "computer-assisted"
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Computer-aided design (CAD)
CAD is used to design, develop and optimize products, which can be fulfill consumers requirement
CAD is extensively used in the design of tools and machinery, and even in the drafting and design of all types of buildings.
CAD is mainly used for detailed engineering of 3D models and/or 2D drawings of physical components,
CAD also used throughout the engineering process from conceptual design and layout of products, through strength and dynamic analysis of assemblies to definition of manufacturing methods of components.
The CAD process. .
Computer-aided design (CAD)
CAD benefits such as lower product development costs and a greatly shortened design cycle.
CAD enables designers to lay out and develop work on screen, print it out and save it for future editing, saving time on their drawings.
Commercial Floor Plan
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Fully editable digital multi-CAD mockup
Fields of use
The Architecture, Engineering, and Construction (AEC) Industry
Architecture
Architectural engineering
Interior Design
Interior Architecture
Building engineering
Civil Engineering and Infrastructure
Construction
Roads and Highways
Railroads and Tunnels
Water Supply and Hydraulic Engineering
Storm Drain, Wastewater and Sewer systems
Mapping and Surveying
(Chemical) Plant Design
Factory Layout
Heating, Ventilation and air-conditioning (HVAC)
Mechanical (MCAD) Engineering
Automotive - vehicles
Aerospace
Consumer Goods
Machinery
Shipbuilding
Bio-mechanical systems
Electronic design automation (EDA)
Electronic and Electrical (ECAD)
Digital circuit design
Electrical Engineering
Power Engineering or Power Systems Engineering
Power Systems CAD
Power analytics
Manufacturing process planning
Industrial Design
Software applications
Apparel and Textile CAD
Fashion Design
Garden design
Lighting Design
Sketchpad
History
A turning point was the development of SKETCHPADsystem in MIT in 1963 by Ivan Sutherland
The distinctive feature of SKETCHPAD was that it allowed the designer to interact with his computer graphically: the design can be fed into the computer by drawing on a CRT monitor with a light pen. Effectively, it was a prototype of graphical user interface, an indispensable feature of modern CAD.
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History
• First commercial applications of CAD -large companies (automotive, aerospace, electronics industries)
1. 1964 GM with DAC-1 (Design Augmented by Computer); ; Bell GRAPHIC 1
2. 1971 Renault (Bezier) – UNISURF car body design and tooling.
• 1971 Dr. P. J. Hanratty, wrote ADAM (Automated Drafting And Machining) code and supplied to companies McDonnell Douglas (Unigraphics), Computervision (CADDS)
• 1960s and 1970s foundation of CAD systems United Computing, Intergraph, IBM, Intergraph IGDS in 1974 (which led to Bentley MicroStation in 1984)
• CAD implementations have evolved dramatically since then.
• 2D in the 1970s, it was typically limited to producing drawings similar to hand-drafted drawings.
• Solid modeling in the 1980s, have allowed more versatile applications of computers in design activities.
History
• 1981 Key products of solid modelling packages launched -Romulus(ShapeData) and Uni-Solid (Unigraphics) based on PADL-2 and the release of the surface modeler CATIA (Dassault Systemes).
• Autodesk was founded 1982 by John Walker, which led to the 2D system AutoCAD.
• The next milestone was the release of Pro/ENGINEER in 1988, which heralded greater usage of feature-based modeling methods and parametric linking of the parameters of features.
• End 80s~early 90s. Ian Braid development the B-rep solid modeling kernels (engines for manipulating geometrically and topologically consistent 3D objects) Parasolid (ShapeData) and ACIS (Spatial Technology Inc.)
• Release of mid-range packages; SolidWorks in 1995, SolidEdge (Intergraph) in 1996, IronCAD in 1998.
• A wire frame model is a visual presentation of an electronic representation of a three dimensional or physical object used in 3D computer graphics
• The wire frame format is also well suited and widely used in programming tool paths for DNC (Direct Numerical Control) machine tools.
wireframe cube, icosahedron, and approximate sphere
A wireframe image using hidden line removal
A surface shaded object (not wireframe)
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CAD Capabilities
2. 3D parametric feature based modelling, Solid modelling (link)
3. Freeform surface modeling
4. Automated design of assemblies, which are collections of parts and/or other assemblies
CAD Capabilities
5. Create Engineering drawings from the solid models
Isometric projection of the object
Sectional views are indicated by the
direction of arrows
Multiple views and projections
1st Angle and 3rd angle projection
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An example of a CAD engineering drawing.
CAD Capabilities
6. Import/Export routines to exchange data with other software packages
There are basically three methods of transferring data from one CAD system to another.• Direct CAD system export/import • Direct 3rd party translators. • Intermediate data exchange formats
1. IGES
2. STEP
3. VDA-FS
4. DXF
5. Parasolid
6. JT
7. DRG
CAD Capabilities
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7. Output directly to a Rapid Prototyping or Rapid Manufacture Machine for
industrial prototypes
8. Reuse of design components
9. Ease of modification of design of model and the production of multiple
versions
10. Automatic generation of standard components of the design
11. Validation/verification of designs against specifications and design rules
12. Simulation of designs without building a physical prototype
13. Output of engineering documentation, such as manufacturing drawings,
and Bills of Materials to reflect the BOM required to build the product
14. Output of design data directly to manufacturing facilities
15. maintain libraries of parts and assemblies
16. calculate mass properties of parts and assemblies
17. aid visualization with shading, rotating, hidden line removal, etc...
CAD Capabilities
The Effects of CAD
Starting in the late 1980s, the development of readily affordable CAD programs that could be run on personal computers
One CAD operator could readily replace at least three or five drafters using traditional methods.
Engineers began to do their own drafting work, further eliminating the need for traditional drafting departments.
This trend mirrored that of the elimination of many office jobs traditionally performed by a secretary as word processors, spreadsheets, databases, etc. became standard software packages that "everyone" was expected to learn.
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Today, hardware and software costs have come down. Even high-end packages work on less expensive platforms and some even support multiple platforms.
The adoption of CAD in engineering schools was not without resistance, however. • sketching on a computer screen did not replicate the skills associated
with practice of sketching in a sketchbook.• students would be hired for their computer skills rather than their
design skill, as was indeed common in the 1990s.
Today, education in CAD is now accepted across the world in schools of engineering.