computer-aided design

computer-aided design (CAD) or computer-aided design and drafting (CADD), form of automation that helps designers prepare drawings, specifications, parts lists, and other design-related elements using special graphics- and calculations-intensive computer programs. The technology is used for a wide variety of products in such fields as architecture, electronics, and aerospace, naval, and automotive engineering. Although CAD systems originally merely automated drafting, they now usually include three-dimensional modeling and computer-simulated operation of the model. Rather than having to build prototypes and change components to determine the effects of tolerance ranges, engineers can use computers to simulate operation to determine loads and stresses. For example, an automobile manufacturer might use CAD to calculate the wind drag on several new car-body designs without having to build physical models of each one. In microelectronics , as devices have become smaller and more complex, CAD has become an especially important technology. Among the benefits of such systems are lower product-development costs and a greatly shortened design cycle. While less expensive CAD systems running on personal computers have become available for do-it-yourself home remodeling and simple drafting, state-of-the-art CAD systems running on workstations and mainframe computers are increasingly integrated with computer-aided manufacturing systems.

computer-aided design (CAD) Use of computer graphics to assist the design of, for example, fabrics, electronic circuits, buildings and vehicles. With CAD, designers can make alterations and analyse their effect. In fabric design, colours may be varied and the effect judged on the computer screen. In vehicle design, road conditions are varied before a prototype is actually built. See also virtual reality

computer-aided design (CAD) The application of computer technology to the design of a product, or the design itself. Computer-aided design is used especially in architecture and electronic, electrical, mechanical, and aeronautical engineering. A computer-aided design uses as inputs both the appropriate technical knowledge of individuals who enter design criteria, edit results, and otherwise test and modify the design, and also accumulated information from libraries of standards for components, element sizes, regulations, etc., such as standard ICs for a digital design system or standard pipe lengths and fittings for a hydraulic or piping system.

Processing of the data from the inputs takes place in at least two phases:(a) certain interactive programs are invoked by the technical designer during the design process, these results being generally displayed on a VDU;(b) programs are applied that may take considerable periods of running time to analyze tolerances, clearances, electrical characteristics, etc., the results of these runs being displayed back to the technical designer.Output from a computer-aided design system consists of printouts of specifications and other information, and machine-readable files that are passed to computer-aided manufacturing (CAM) systems and computer-aided testing (CAT) systems. Examples of output to a CAM system are computer-produced artwork for printed circuit boards, or computer-produced tapes for automatic component insertion and board drilling. The combined process of computer-aided design and manufacture is known as CADCAM. The whole procedure – design, manufacture, and testing – is often referred to as CADMAT. There is an ISO standard (STEP) for the exchange of product model data, including CAD data.