| Computer-aided design (CAD) is the use of a | | | | The term "computer-aided design" was coined |
| wide range of computer-based tools that | | | | by Doug Ross at MIT in 1959.[6] |
| assist engineers, architects and other design | | | | |
| professionals in their design activities. It | | | | It is argued that a turning point was the |
| is the main geometry authoring tool within | | | | development of SKETCHPAD system in MIT in |
| the Product Lifecycle Management process and | | | | 1963 by Ivan Sutherland (who later created a |
| involves both software and sometimes | | | | graphics technology company with Dr. David |
| special-purpose hardware. Current packages | | | | Evans). The distinctive feature of SKETCHPAD |
| range from 2D vector based drafting systems | | | | was that it allowed the designer to interact |
| to 3D solid and surface modellers. | | | | with his computer graphically: the design can |
| | | | be fed into the computer by drawing on a CRT |
| CAD is sometimes translated as | | | | monitor with a light pen. Effectively, it was |
| "computer-assisted", "computer-aided | | | | a prototype of graphical user interface, an |
| drafting", or a similar phrase. Related | | | | indispensable feature of modern CAD. |
| acronyms are CADD, which stands for | | | | |
| "computer-aided design and drafting", CAID | | | | First commercial applications of CAD were in |
| for Computer-aided Industrial Design and | | | | large companies in the automotive and |
| CAAD, for "computer-aided architectural | | | | aerospace industries, as well as in |
| design". All these terms are essentially | | | | electronics. Only large corporations could |
| synonymous, but there are some subtle | | | | afford the computers capable of performing |
| differences in meaning and application. | | | | the calculations. Notable company projects |
| | | | were at GM (Dr. Patrick J.Hanratty) with |
| CAD was originally the three letter acronym | | | | DAC-1 (Design Augmented by Computer) 1964; |
| for "Computer Aided Draughting" as in the | | | | Lockhead projects; Bell GRAPHIC 1 and at |
| early days CAD was really a replacement for | | | | Renault (Bezier) – UNISURF 1971 car |
| the tradition draughting board. But now is | | | | body design and tooling. |
| the term is often interchanged with "Computer | | | | |
| Aided Design" to reflect the fact that modern | | | | One of the most influential events in the |
| CAD tools do much more than just draughting. | | | | development of CAD was the founding of MCS |
| | | | (Manufacturing and Consulting Services Inc.) |
| Introduction | | | | in 1971 by Dr. P. J. Hanratty[7], who wrote |
| | | | the system ADAM (Automated Drafting And |
| CAD is used to design, develop and optimize | | | | Machining) but more importantly supplied code |
| products, which can be goods used by end | | | | to companies such as McDonnell Douglas |
| consumers or intermediate goods used in other | | | | (Unigraphics), Computervision (CADDS), Calma, |
| products. CAD is also extensively used in the | | | | Gerber, Autotrol and Control Data. |
| design of tools and machinery used in the | | | | |
| manufacture of components, and in the | | | | As computers became more affordable, the |
| drafting and design of all types of | | | | application areas have gradually expanded. |
| buildings, from small residential types | | | | The development of CAD software for personal |
| (houses) to the largest commercial and | | | | desk-top computers was the impetus for almost |
| industrial structures (hospitals and | | | | universal application in all areas of |
| factories). | | | | construction. |
| | | | |
| CAD is mainly used for detailed engineering | | | | Other key points in the 1960s and 1970s would |
| of 3D models and/or 2D drawings of physical | | | | be the foundation of CAD systems United |
| components, but it is also used throughout | | | | Computing, Intergraph, IBM, Intergraph IGDS |
| the engineering process from conceptual | | | | in 1974 (which led to Bentley MicroStation in |
| design and layout of products, through | | | | 1984) |
| strength and dynamic analysis of assemblies | | | | |
| to definition of manufacturing methods of | | | | CAD implementations have evolved dramatically |
| components. | | | | since then. Initially, with 2D in the 1970s, |
| | | | it was typically limited to producing |
| CAD has become an especially important | | | | drawings similar to hand-drafted drawings. |
| technology with benefits, such as lower | | | | Advances in programming and computer |
| product development costs and a greatly | | | | hardware, notably solid modeling in the |
| shortened design cycle, because CAD enables | | | | 1980s, have allowed more versatile |
| designers to lay out and develop their work | | | | applications of computers in design |
| on screen, print it out and save it for | | | | activities. |
| future editing, saving a lot of time on their | | | | |
| drawings. | | | | Key products for 1981 were the solid |
| | | | modelling packages -Romulus (ShapeData) and |
| Designers have long used computers for their | | | | Uni-Solid (Unigraphics) based on PADL-2 and |
| calculations. Initial developments were | | | | the release of the surface modeler CATIA |
| carried out in the 1960s within the aircraft | | | | (Dassault Systemes). Autodesk was founded |
| and automotive industries in the area of 3D | | | | 1982 by John Walker, which led to the 2D |
| surface construction and NC programming, most | | | | system AutoCAD. The next milestone was the |
| of it independent of one another and often | | | | release of Pro/ENGINEER in 1988, which |
| not publicly published until much later. Some | | | | heralded greater usage of feature-based |
| of the mathematical description work on | | | | modeling methods and parametric linking of |
| curves was developed in the early 1940s by | | | | the parameters of features. Also of |
| Isaac Jacob Schoenberg, Apalatequi (Douglas | | | | importance to the development of CAD was the |
| Aircraft) and Roy Liming (North American | | | | development of the B-rep solid modeling |
| Aircraft), however probably the most | | | | kernels (engines for manipulating |
| important work on polynomial curves and | | | | geometrically and topologically consistent 3D |
| sculptured surface was done by Pierre Bezier | | | | objects) Parasolid (ShapeData) and ACIS |
| (Renault), Paul de Casteljau (Citroen), | | | | (Spatial Technology Inc.) at the end of the |
| Steven Anson Coons (MIT, Ford), James | | | | 1980s and beginning of the 1990s, both |
| Ferguson (Boeing), Carl de Boor (GM), | | | | inspired by the work of Ian Braid. This led |
| Birkhoff (GM) and Garabedian (GM) in the | | | | to the release of mid-range packages such as |
| 1960s and W. Gordon (GM) and R. Riesenfeld in | | | | SolidWorks in 1995, SolidEdge (Intergraph) in |
| the 1970s. | | | | 1996, and IronCAD in 1998. Today CAD is one |
| | | | of the main tools used in designing products. |