CAD
- 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 in their design activities. It involves both software and special-purpose hardware.
CAD is sometimes translated as "computer-assisted design", "computer-aided drafting", or a similar phrase. A related acronym, CADD, stands for "computer-aided design and drafting". All these latter terms are essentially synonymous, and refer to the designing and technical drawing of various projects on a computer rather than a traditional drawing board. The spectrum of 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 (so-called "IP")
- 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
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)
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