Computer-assisted design, CAD

CAD (computer-assisted design) CAD/CAM (computer-assisted design and manufacturing)... 

Many chemical and petroleum companies are now using Process Industry Practices (PIP) criteria for the development of P IDs. These criteria include symbols and nomenclature for typical equipment, instrumentation, and piping. They are compatible with industry codes of the American National Standards Institute (ANSI), American Society of Mechanical Engineers (ASME), Instrument Society of America (ISA), and Tubular Exchanger Manufacturers Association (TEMA). The PIP criteria can be applied irrespective of whatever Computer Assisted Design (CAD) system is used to develop P IDs. Process Industries Practice (1998) may be obtained from the Construction Industry Institute mentioned in the References. 

Developments. A variety of process modifications aimed at improving surface finish or weld line integrity have been described. They include gas assisted, co-injection, fusible core, multiple Hve feed, and push—pull injection mol ding (46,47). An important development includes computer-aided design (CAD) methods, wherein a proposed mold design is simulated by a computer and the melt flow through it is analy2ed (48). 

The introduction of computers to many companies allows proprietary software to be used for layout design. Spreadsheet, mathematical modeling and computer-aided design (CAD) techniques are available and greatly assist the design process, and have added to the resources available to planners. However, the traditional scale models described above will still be useful to present the result to management and shop floor personnel. 

Figure 4.4 CAD, computer-assisted design ID identification SAR, structure-activity relationship...

In the revised Chapter 11 there is material added to call attention to the importance of material and process interaction when using the computer-assisted design methods. At present this is an area where the lack of data poses a limitation to the application of CAD/CAM. 

Computer-aided design (CAD) uses the mathematical and graphicprocessing power of the computer to assist the mechanical engineer in the creation, modification, analysis, and display of designs. Many factors have contributed to CAD technology becoming a necessary tool in the... 

Our case study provided evidence of automation bias effects in the use of CAD effects which could not be attributed to complacency and could actually coexist with users reported mistrust towards the tool [35]. Previous studies had concluded that on average using CAD was either beneficial or ineffectual. Our analyses indicated instead that CAD reduced decision errors by some readers on some cases but increased errors by other readers on some cases. In short, this simple computer-assisted task hid subtle effects, easy to miss by designers and assessors [37]. 

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