Computer-aided design

Data processing and assistance with the design.

Any technical system is the association of functions. The fitting of these functions, their interactions, the possible incompatibilities belong to the knowledge of the Engineer. When the system is affected of a too large number of Paramètre S, it becomes difficult all to control. The CAD makes it possible to conceive systems whose complexity exceeds the capacity of the human being such as for example in Micro-électronique. The virtual design allows the overall assessment of the behavior of the object created before even as this one does not exist. In CAD, one does not draw, one virtually builds an object able to react in his nonreal space according to laws controls by the Logiciel. The result, called numerical Maquette constitutes true a then prototype evolutionary.

Each trade association can have a tool CAD. In mechanics, one can design a part where each form meets a need for operation as well as a mechanism gathering several parts. In electronics, one can assemble components (resistances, capacities, elements of logic…) which can be simulated: for example " will be able; construire" new a Microprocessor gathering several million transistors (3,1 for the Pentium). In a certain way, CAM falls under this whole of tools of assistance to the design (creation of documents).

The CAD took off in years 75-90, when the cost of installation of a station approached the annual cost of a draftsman. The installation was a little painful at the beginning because of a need for taking again the existing plans. One seen on this occasion that statistically nearly 10% of quotations on the existing levels was inaccurate, that references of plans existed in double, that a single reference could correspond to several slightly different plans, etc At the end of the day, profit of reliability of information proved to constitute an important additional argument deciding to generalize the CAD.

The material

The CAD is known to be still in 2007 one of the greediest computer applications in computer's resources. After years of only presence of this software on work stations using of the system operative and material architectures owners (Sun, IBM, Computervision, HP, Apollo, SGI, in the past Silicon Graphics …), one will have needed the development of personal computers (PC or MAC) sufficiently powerful to ensure of the very heavy functions in numerical calculation:

numerical modeling;
mechanical simulation and calculation of materials;
chart;
drawing of plan;
handling of objects 3D;
management of great assemblies.

That made CAD an important application of data processing.

Its strategic importance results in making him use models allowing the communication of information between machines, by means of standards like IGES, in order to not depend neither on only one type of material, nor (too much) of only one software. Many projects of CAD in addition utilize of the dispersed subcontractors and it matters that the representations are perfectly compatible in order to allow work in collaboration and remote. It is what was made for the modification of architecture of the CNIT in 1987.

One quickly takes conscience of the importance of the CAD in any urban environment, formed of objects which all without exception were drawn before being one day manufactured .

Field of application

Mechanics

The field of mechanics is historically one of first has to have known applications of the CAD. It makes it possible it automatically to take into account a great number of constraints (Résistance of the materials, capacity of assembly, manufacture, etc) during the phase of design of a unit. The Logiciel S correspondents are used at the time of one or several phases of the development.

The software used allows a direct design in three dimensions, are especially interesting for the functionalities suggested: today a part of sheet-iron works is modelled by virtually folding sheet, a drilling is placed of a simple click, without having to think on the choice of the voluminal forms - of the mathematical direction to adopt to model its matter. If the first software proposed a fixed history (not possible final improvement of the already definite forms) the last versions using the parametric Conception all the modifications authorize.

This software contributes not only with the creation of the parts Mécanique S, or with the implementation of their manufacture, but also with the Simulation of their Comportement, and thus to the validation of the adopted solutions.
Once finished creation, the automatic execution of the plans, respecting the conventions of representation is a play of child. The mode switch-over 2D is not any more arises from the draftsman to the difference with the Dessin computer-assisted which requires to control at the same time, and at the same time, the bottom (what one wants to represent) and the form (the feature on the plan), concepts which are independent for the software.

The functional Quotation, and quotation on the principle of independence are from now on easier with the software tools in parametric design. What at summer thought when designing part is reflected with the good dimension at the time of the setting in automatic plan. This work is additional for the technician using a tool of Dessin computer-assisted (CAD).

Electronics

The construction industry

Software exists for the design of building and building.

Arcad
ArchiCAD, of the company Graphisoft
Allplan, of the company Nemetschek - http://www.nemetschek.fr/- IT solution for the design, the construction and the management of buildings and real goods. Software structures.
AutoCAD
VectorWorks, of the company Nemetschek
Microstation, of the company Bentley - http://www.abscisse-info.com/- Retailer approved by Bentley (formations and service 2d and 3D.

molecular

Clothes industry

… of clothing (for example Modaris of Lectra, Accumark To stack Technology…), trade which presents the characteristic of the management of the sizes…

Orthopedy

The software of CAD replaces today little by little the plaster in the daily work of the Orthopedist-orthésiste. The plastered moulding of the patient is indeed supplanted by techniques of modeling 3D (using for example a camera). The form 3D obtained is then modified by a software of CAD in order to design the orthopedic equipment adapted to the patient (corset, prosthesis,…).

Other trade associations

… of gardens and even the space visualization of molecules ( Rasmol ). They then take again the initials of CAD to which one often affixes a qualifier (as in Electronic CAD or molecular CAD ), which shows the success of this terminology.

Living room

Micad

Standard interchange formats

Mechanical CAD

See also: assisted mechanical Design par_ordinator

Electronic CAD

See also: CAD électronique#Formats of exchange

Orthopedic CAD

AAOP

See too

Acronyms of the parametric CFAO
Design
Drawing computer-assisted (CAD)
Manufacture computer-assisted (FAO)
Data-processing musical
numerical Prototyping
Model
data-processing Rasmol
Simulation
Stéréolithographie
Work station
Groupware

External bonds

discussion forum CAD

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