CAD systems are computer-aided design systems that are used to perform a variety of design procedures involving computer technology. Also, with the help of such software, technological and design documentation is created for individual buildings, products or structures. Modern CAD systems are used in the most diverse fields of activity of a modern person, and almost everyone has their own unique type of such utilities.
What it is?
Often, the acronym CAD is considered to be the standard English-language analogue of the term CAD, but in fact this is not entirely true. CAD systems cannot be considered as a full-fledged analogue of CAD as an organizational and technical system, since GOST gives this phrase in the form of a standardized English-language equivalent of the term “computer-aided design”. Thus, the term CAD is translated into English more as a CAE system, but a number of foreign sources indicate that the term CAE is a generalized concept that includes the use of any computer technology in engineering, including CAM and CAD.
Why is this needed?
CAD systems are mainly used in order to maximize the efficiency and productivity of engineers through the complete automation of design and further preparation of production. Thus, due to their application, the following advantages are achieved:
- design time is significantly reduced;
- the amount of labor required for planning and design is reduced;
- significantly reduces the total cost of manufacturing and design, which directly affects operating costs;
- increasing the technical and economic level, as well as the quality of the results of the design work;
- reduction of costs required for testing and field modeling.
Modern CAD systems use various technical knowledge of experts as input, which refine the results, introduce various design requirements, verify the resulting structure, change it and many other things.
Implementation of the computer-aided design system is carried out as a complex of applied utilities, with the help of which design, as well as further drawing and three-dimensional modeling of structures or volume and flat parts are provided.
In the predominant majority of cases, CAD systems include modules for modeling three-dimensional structures, as well as design drawings and various design text documents.
They are classified mainly according to several parameters:
- variety and type of the object in question;
- level of automation of the design procedure;
- the complexity of the created object;
- the complexity of the automation process;
- number of documents used;
- the nature of the documents used;
- the total number of levels that will be present in the structure of technical support.
Special purpose
Depending on the tasks of the CAD systems, they are divided into several groups:
- Automation of three-dimensional or two-dimensional geometric design, as well as the creation of various technological or design documentation.
- Design and further creation of drawings.
- Maintaining geometric modeling.
- Automation of various engineering calculations, conducting dynamic modeling, as well as analysis and simulation of physical processes with subsequent verification and optimization of products.
- A subclass of CAE tools used for computer analysis.
- Means intended for the technological preparation of the production process of various products, which allows for automation of the programming procedure and further control of equipment with GAPS or CNC.
- Tools designed to automate the planning processes of various technological processes used at the junction of CAM and CAD systems.
Most computer-aided design systems can combine the solution of various problems that relate to different aspects of design - a comprehensive or integrated computer-aided design (CAD) system.
Generally accepted international classification
Modern classification distributes them into several categories:
- drawing-oriented systems that first appeared in the seventies of the last century, but can still be used in some situations;
- systems that create three-dimensional electronic models of objects, due to which it becomes possible to solve various problems associated with modeling up to the production procedure;
- systems with which the concept of a complete electronic description of an object is supported.
The latter type is a technology that provides the development and subsequent support of an information electronic model throughout its entire life cycle, including conceptual and detailed design, full-fledged marketing, production, technological preparation, operation, as well as utilization and repair.
In modern technical and educational literature, as well as various state standards, the CAD abbreviation is interpreted as “Computer-aided design system”, but at the same time, the concept “Computer-aided design automation system” most closely corresponds here, but it is more difficult to understand, therefore it is found much less often . It often happens that, when conducting design in CAD systems, one may notice an incorrect interpretation of the “Automatic Design System”, although in reality this is essentially erroneous. Do not forget that the concept of “automatic” provides for completely independent operation of the system without the need for any human involvement, while CAD nevertheless requires the execution of certain tasks by the person himself, and full automation refers only to individual procedures and operations .
Not quite true is also such a concept as “Software tool for computer-aided design”, as it can be called too narrowly focused. Of course, at the moment CAD is considered exclusively as the application software necessary for carrying out project activities, but in fact, in the domestic literature and various state standards CAD is considered as a more voluminous concept, which includes not only software tools.
CAD in dentistry
The vast majority of modern dental clinics use CAD. CAD systems in dentistry are used to produce high-quality dentures; for more than ten years now they have been used for the manufacture of abutments for implants, crowns and all kinds of prostheses, all of which are of excellent quality and high precision. The essence of this technology lies in the fact that initially three-dimensional modeling of the created structure is carried out on a computer, and only then, using the design model, they are manufactured on the milling unit.
Thus, dentists get a lot of advantages due to the use of CAD technology in their work. CAD systems in dentistry are most often used as follows:
- first, the doctor takes a cast, which is then sent to the laboratory;
- after delivery, the mold is placed in a specialized scanner that creates a model of the future product;
- the CAD system comes into play: the 3D model turns into a specialized file that will serve as a data source for the milling unit;
- using the resulting file, on the milling unit, the frame is manufactured from a special blank made of zirconium oxide;
- in the end, the resulting frame is carefully coated with a ceramic mass and baked.
CAD / CAM systems in dentistry make it possible to make zirconia crowns, which differ from metal-containing products by a host of advantages. By themselves, these products have practically no color differences from natural teeth, since the choice of shade is carried out in the process of manufacturing the frame. Further, the frame is carefully covered with a special ceramic mass, which has a translucent and translucent structure, and also includes a fairly wide range of colors in its palette, due to which it is possible to produce crowns similar to natural teeth.
By itself , zirconium oxide is highly biocompatible, even when compared with precious metals, and is a hypoallergenic material, which was confirmed in the course of a number of scientific clinical studies. However, in fact, crowns based on a zirconium oxide framework are far from the only type of products for the manufacture of which CAD / CAM systems are used. CNC machine based on such technologies allows to produce:
- various bridges;
- temporary crowns ;
- individual abutments.
In addition to the zirconia already mentioned, a wide variety of materials can be used in the manufacturing process, including plastic, wax, cobalt and titanium, chromium.
What are the benefits?
These technologies provide benefits such as:
- maximum possible manufacturing accuracy with slight deviations;
- full automation of production processes, which almost completely eliminates the likelihood of errors;
- the possibility of using a number of materials;
- the ability to carry out modeling and production procedures in different places;
- ultimate productivity of any ongoing processes.
CAD in mechanical engineering
CAD-system (T-FLEX CAD and others) is quite widespread in the field of engineering, which differs into three levels - lower, middle and upper. Such a division appeared at the turn of the eighties and nineties of the last century.
The lower level includes low-cost CAD / CAM / CAE systems that mainly focus on 2D graphics, that is, are mainly aimed at providing automation of drawing works. As the technical support for lightweight CAD systems, personal computers were used, which at that time were significantly inferior in functionality to full-fledged workstations.
Top-level systems, or, as they are also called, heavy CAD systems, were developed in order to be used on all kinds of mainframes or workstations. Such systems turned out to be much more universal, but at the same time they had a rather high cost, focusing mainly on surface and solid modeling. The design of a variety of drawing documentation in them is often carried out through the preliminary development of special geometric three-dimensional models. After this, systems in which the 3D modeling function was limited exclusively to solid models, that is, occupying an intermediate position between heavy and light, got their own, average level.
To date, the development of CAD has already led to the fact that in most mid-level systems, special tools for surface modeling have begun to appear, and the functions available for use in personal computers have also become acceptable for modern top-level systems. Due to this, even those principles that previously distinguished between medium and heavy systems have changed. Modern heavy-level CAD systems are now called CAE / CAD / CAM / PDM, that is, those that simultaneously include features such as:
- technological and design engineering;
- engineering analysis;
- project information management;
- expanded composition of special software modules.
In contrast, modern mid-tier systems are commonly called mainstream, mid-range, or simply serial.
Systems of one level can be called approximately equivalent in terms of functionality, since some new achievements appearing in a certain program-methodological complex will be soon implemented in new versions of others. In CAD of large companies, it is often enough common to combine several systems of different levels at the same time. This is often due to the fact that almost all design procedures can be carried out on middle and lower level CAD systems, and in addition, heavy ones are too expensive. It is for this reason that enterprises buy licenses of top-level programs in a rather limited quantity, and the overwhelming majority of modern client bases are provided at the expense of the lower and middle levels.
Moreover, quite often it happens that CAD / CAE systems can have certain problems in terms of exchanging information with each other, but such troubles are solved by using special formats and languages adopted in CALS technologies, although to ensure undistorted transmission of geometric data through intermediate unified languages have to overcome some difficulties.
Structure
Like any other complex system, CAD includes several subsystems that can be design or maintenance.
The former are directly involved in a variety of design work. As an example of such, we can cite subsystems of three-dimensional geometric modeling of various mechanical objects, circuit analysis, creation of design documentation, or tracing the connections of printed circuit boards.
The service subsystems are intended to ensure the normal working capacity of the projectors, and their combination is often called among the specialists the CAD system environment. As typical service subsystems, project management data bases, various subsystems for the development and subsequent maintenance of CASE software, as well as training subsystems designed to facilitate the development of CAD technologies by users are often used.
Structuring on various aspects has allowed the appearance of CAD systems, which today stand out only seven:
- technical, which includes various hardware ;
- mathematical, combining all kinds of mathematical methods, algorithms and models;
- software representing computer programs CAD;
- informational, which includes databases, management systems for these databases, as well as many other information used in the design process;
- linguistic, expressed in the form of communication languages between computers and designers, data exchange languages between CAD hardware and programming languages;
- methodical, which includes all kinds of design technologies;
- organizational, made in the form of job descriptions, staffing tables and other documentation, with the help of which the regulation of the work of project enterprises is carried out.
It is worth noting that the entire body of information that is used in the design process is called by the CAD information fund by specialists. The database is an ordered set of information, which reflects the various characteristics of objects and their relationship in a particular subject area. Access to the database for studying, recording and subsequent data adjustment is carried out through the DBMS, and the set of DBMS and DB is usually called BND, that is, a data bank.
Classification
CAD / CAM design systems are classified according to a number of characteristics, such as application, purpose, scale (how comprehensively the tasks are solved), and the nature of the basic subsystem.
According to applications, among the most popular and representative, it is worth highlighting the following CAD groups:
- used in the field of general engineering (due to which they are usually called engineering);
- used in the field of electronics;
- used in construction and architecture.
In addition, there is also a fairly large number of specialized systems either allocated in the listed groups, or representing a completely independent branch of the classification. As an illustrative example, CAD can be used for large integrated circuits, electrical machines, aircraft, and a number of others.
The scale distinguishes between individual software and methodological complexes, including a complex for checking the strength of various mechanical products according to the finite element method or a complex for checking electronic circuits, as well as systems with a unique architecture of not only software, but also hardware.
Base subsystem
The following types of CAD exist here:
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