Computer-aided design
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- This article is about computer-aided design. For other meanings, see CAD (disambiguation).
Computer-aided design (CAD) is the use of a wide range of computer-based tools that assist engineers and architects in their design activities. It involves both software and special-purpose hardware.
CAD is sometimes translated as "computer-assisted", "computer-aided drafting", or a similar phrase. Related acronyms are CADD, which stands for "computer-aided design and drafting", and CAAD, for "computer-aided architectural design". All these latter terms are essentially synonymous, and refer to the designing and technical drawing of various projects by use of a computer rather than a traditional drawing board. The spectrum of architectural and engineering projects commonly created with computer-aided drafting is broad, and include architectural drafting, mechanical drafting, electrical drafting, and other forms of design communication. Today they constitute part of a broader definition of computer-aided design.
Designers have long used computers for their calculations. It is argued that a turning point was the development of SKETCHPAD system in MIT in 1963 by Ivan Sutherland. The distinctive feature of SKETCHPAD was that it allowed the designer to interact with 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.
First commercial applications of CAD were in large companies in automotive and aerospace industry, as well as in electronics. As computers became more affordable, the application area gradually expanded.
CAD implementations have evolved dramatically since then. When the field was initially established it was typically limited to producing drawings similar to hand-drafted drawings. Advances in computer technology have allowed more skillful application of computers in design activities. Today CAD is not limited to drafting and rendering, and it ventures into more "intellectual" areas of designer's expertise.
The capabilities of modern CAD systems include:
- Reuse of design components
- Ease of design modification and versioning
- Automatic generation of standard components of the design
- Validation/verification of designs against specifications and design rules
- Simulation of designs without building a physical prototype
- Automated design of assemblies, which are collections of parts and/or other assemblies
- Output of engineering documentation, such as manufacturing drawings, and Bill of Materials
- Output of design directly to manufacturing facilities
- Output directly to a Rapid Prototyping or Rapid Manufacture Machine for industrial prototypes
Development in CAD resulted in the following tools and methods:
- Wireframes
- Solid modelling
- Intelligent wiring diagrams and production linked database systems
- Graphically represented system or plant diagrams and databases
- Parametric design models
- Real-time process simulation
- Computer Numerically Controlled (CNC) load files (toolpath instructions)
- Finite Element Analysis (FEA)
- Rapid prototyping
Many CAD drawings are created from scratch using the application software using design sketches and other inputs. Other CAD drawings are created from pre-existing electronic CAD files by copying all or part of another CAD file, making changes, then saving it as a new file. Drawings that only exist in physical form (blueprints, plots of lost files, etc.) can be converted into CAD files using a procedure called "Paper-to-CAD conversion", drawing conversion, digitization, or vectorization.
See also
- Computer-aided engineering (CAE)
- Computer-aided manufacturing (CAM)
- Computer graphics
- Electronic design automation (EDA)
- List of CAD companies
- New product development
- Paper-to-CAD conversion
- Pierre Bzier
- List of open-source software packages#CAD
da:Computer aided design de:Computer Aided Design es:CAD fr:Conception assiste par ordinateur he:עיצוב ממוחשב nl:Computer Aided Design ja:CAD pl:Komputerowe wspomaganie projektowania pt:CAD sl:Računalniško_podprto_načrtovanje sv:CAD zh:CAD
External links
- Design Council on Computer Aided Design (http://www.designcouncil.org.uk/cad/) Design Council one stop shop information resource on CAD by Paul Siodmok.
- CAD Systems in Education (http://www.emlabs.info/taxonomy/term/9,33) List of CAD systems developed in Universities for educational and commercial use.