History of the development of computer-aided design systems. Experience in the implementation of CAD at domestic enterprises of the machine-building industry
Computer-aided design of technological processes (CAD TP) is a set of design automation tools interconnected with the necessary departments of the design organization or a team of specialists (system users) that performs computer-aided design.
The main area of application of CAD TP is machining production of various degrees of automation. It is allowed to use the system for automated development of TP for sheet stamping, welding, assembly, and others, as well as the use of system tools for solving various applied problems (economic, information retrieval, etc.).
The main output product of CAD TP is the TP library, which is a non-systematized set of TP files. In the future, a bank of technological processes (BTP) will be developed, i.e., an orientation towards “paperless” technological documentation has been adopted. BTP is a set of information models of individual (single), typical and group TP. The TP information model (IMTP) is a set of specially organized data that contains all the information about the TP, the composition of which is determined by the relevant standards. Additionally, IMTP stores information intended for use by the CAD TP itself, as well as by other related automated systems for technological preparation and production management.
CAD TP provides automatic preparation of text technological documents in accordance with the ESTD-2 standards and control programs in the format of CNC systems.
CAD TP provides an increase in labor productivity of technologists for the development of TP and control programs by 3 ... 10 times, in some cases up to 50 times.
The composition of the system. CAD TP is a set of software and information support tools. When developing the system, a focus was made on the creation of tools (a structured set of software tools) for the development of specific CAD TP. These tools enable the development of CAD TP by subject specialists (technologists) who do not have deep knowledge in the field of programming. Such opportunities are provided by a specially developed language of technological algorithms and a data description language.
CAD TP tools are an advanced programming system, problem-oriented for technological CAD, which includes a number of subsystems:
translator from the language of technological algorithms;
database preparation system:
description of the data in the dialog mode;
description of data in batch mode;
database table translator;
extracting tables from databases;
entering tables into the source database;
knowledge base builder designed to create and modify a knowledge base;
link editor designed to establish links (in the form of table and column addresses) of the knowledge base with the information model of the technological process (IMTP) and with the database;
IMTP equalizer, which makes it possible to use the previously designed TP when modifying the IMTP upwards;
subsystem for online viewing of design results;
subsystem for checking the structure of TP;
graphic display subsystem designed for graphic control of design results;
an executing system that is used to implement knowledge base algorithms;
executing system debugger (for debugging programs written in the language of technological algorithms).
The possibility of using tools in various related applied tasks is not excluded.
The basic set of the system consists of the information support of the database (DB) and the knowledge base (KB).
2. Automation of calculations of cutting conditions
For processing each of the surfaces of parts in the case of using CNC machines, it is necessary to calculate the tool paths.
Obviously, in this case, it is necessary to ensure the specified accuracy of the machined surfaces at minimal cost, taking into account the technological capabilities of the machine and tool. For turning, in the general case, it is necessary to determine the trajectory of the tool, its feed and the revolutions of the machine spindle.
Then, at the 2nd stage, the processing modes are determined. The search is carried out in order to achieve a minimum cost for surface treatment.
Finding the optimal cutting mode:
To calculate the cutting conditions, the trajectories of the tool movement and the characteristics of the quality of the surface of the parts must first be known. The search for optimal modes can be carried out with known mathematical dependencies between processing modes, acting forces, quality and reliability of parts, and restrictions in the machine system for the strength of its elements, drive power and ranges of allowable feeds and revolutions. Otherwise, optimization by processing modes is not feasible and they are selected based on the recommended experimental data using IPS computers.
To find the optimal surface treatment modes, it is most simple to use linear programming methods. This is due to the fact that the current restrictions and the objective function are reduced to linear dependencies by taking a logarithm.
It is known that the optimization of cutting conditions allows the use of more productive modes compared to the normative ones. The use of optimal cutting conditions allows 5-7%, and in some cases more, to increase labor productivity. In the conditions of single and small-scale production, which is just typical for instrument making, work on optimizing cutting conditions is usually not carried out. The economic effect obtained from the optimization of cutting conditions when processing small batches of parts is small and most often cannot compensate for the costs of optimization. Therefore, an experienced worker usually empirically selects cutting conditions that allow him to achieve maximum labor productivity, with a given product quality. At the same time, the optimization of cutting conditions, performed in CAD TP, allows the worker to reduce the period of setting the machine for optimal performance, which is especially important when processing small batches of parts on expensive CNC metal-cutting equipment.
Let us briefly consider the principles of optimizing cutting conditions. To determine the cutting conditions, it is necessary to have a mathematical model of the machining process, i.e. have a system of equations in which V, S and t are associated with the parameters of the AIDS system. This model was first proposed by Prof. G.K. Goransky. The model is a system of inequalities. Each inequality expresses some limitation of the area of permissible cutting conditions. For example, restrictions on the permissible cutting speed, on the permissible surface roughness, and so on.
Automation of technological norms of time
The normalization of the technological process consists in determining the value of the piece time Tsh for each operation. Below is an algorithm for one of the most common cases of sequential surface treatment of parts on metal-cutting machines.
Legend: t mouth , t withdrawn - time for installation and removal of the part on the machine; t i - execution time of the i-th transition; T To - execution time of k-th operation; WITH To - the number of surfaces and elements of parts processed on the k-th operation; P, S - intermediate variables. The piece time includes set-up time, take-down time, and transition time. The algorithm (Fig. 2.1) provides for the processing of information for a given sequence of TP. The sign of the end of the vector C is the zero value of the last component. Analysis at the end of the vector is performed using the 5th step of the algorithm. The accumulation of piece time for each operation is performed using steps 7-11. The variable P serves as a counter for the number of transitions in the operation. The initial value P is selected from the vector C using step 6. The piece time is calculated for each of the TP operations. The technologist has the ability, based on the results obtained, to change the composition of operations using the vector C. Rice. 2.1. Scheme of the algorithm for calculating piece time automation technological cutting 3. Prepare the initial data for the development of TP MO
The starting part is a stepped shaft. Material Steel 45 GOST 1050-88 Billet - forging Production - medium series harvesting operation Cutting the workpiece to the desired length Equipment - circular copy machine 8G642 Equipment - vise Cutting tool - cutting cutter Sketch: Operation: turning and cutting Roughing, finishing of external cylindrical surfaces with an allowance for grinding, trimming ends, chamfers. Cutting tool: Straight cutter with mechanical fastening of a hard alloy plate, right 2103-0713 GOST 20872-80 Straight cutter with mechanical fastening of the hard alloy plate, left 2103-0714 GOST 20872-80 Straight cutter with mechanical fastening of a hard alloy plate, right 2103-0713 GOST 20872-80 Turning cutter for turning angular grooves with mechanical fastening of a hard alloy plate, left K.01.4528.000-01 Sketch: Sharpen a diameter of 54.8 mm for a length of 13.5 mm with a grinding allowance of 0.5 mm. Sharpen a diameter of 55 mm on a length of 27 mm with a grinding allowance of 0.5 mm. Sharpen a diameter of 99 mm on a length of 22.5 mm with a grinding allowance of 0.5 mm. Make a groove 3 mm long to a depth of 1.5 mm 030 - Operation: drilling Drilling a through hole, chamfering. Equipment: Screw-cutting lathe 16K20F3 Equipment: Three-jaw self-centering chuck 7100-0009 GOST 2675-80 Rotating center A-1-4-NP CNC GOST 8742-75 Cutting tool: 6. Drill with a diameter of 18 mm. OST 2 I41-14 Through-hole cutter c = 45 with mechanical fastening of the hard alloy plate, right 2102-0191 GOST 21151-75 Passing cutter c = 45 with mechanical fastening of the hard alloy plate, left 2102-0192 GOST 21151-75 Measuring tool: vernier caliper ShTs-2-160-0.05 GOST 166-90 Sketch: Drill a through hole with a diameter of 18 mm Chamfering 1.6x45 Chamfering 1.6x45 Operation 040 - drilling Drilling three stepped through holes Equipment: Cantilever vertical milling machine VM-127M Tooling: Dividing head UDG-D250 Cutting tool: 9. Drill with a diameter of 9 mm. OST 2 I41-14 End mill with a diameter of 14 mm GOST 17026-71 Sketch: Drill through holes with a diameter of 9 mm Drill blind holes with a diameter of 15 mm to a depth of 7 mm Operation 045 - Locksmith Filing burrs, dulling sharp edges. Equipment: locksmith workbench Tool: file. Operation 050 - Grinding of diameters 55h6, 36h6 with face grinding Ra0.8. Equipment: Model 3151 Cylindrical Grinding Machine. Tool: grinding wheel. Measuring tool: vernier caliper ShTs-2-160-0.05 GOST 166-90, micrometer. Operation 050 - Washing Equipment: washing machine. Operation 055 - Control Equipment: OTK table. Literature
1. Stupachenko A.A. CAD of technological operations - L. Mashinostroenie - 1988 Krivoruchenko E.M., Lapitsky D.I., Grebenyuk G.G. Automated control system for the supply of production orders with tools and technological equipment. // Scientific session MEPhI-2006. Collection of scientific papers. In 16 volumes. T.2. Software. Information Technology. M.: MEPhI, 2006. 168 p.
In Russian production, it is customary to include CAD, CAE and CAM in the concept of a computer-aided design system (CAD), although foreign designers associate CAD only with CAD. Be that as it may, CAD is a set of programs for drawing two-dimensional and three-dimensional objects, creating design and technical documentation. According to the created model, it is possible to generate product drawings and their support.
SAE - a system for automation of engineering calculations and analysis, CAM - a system for automated processing of parts for CNC machines and production lines.
When choosing a CAD for a design organization or department (and the choice is really wide - more than 50 software titles), you should pay attention not only to the price of the software package, but also to other important parameters, for example, user-friendliness of the interface, the possibility of teamwork, the volume of the standard library of components and solutions, ease of interfacing with other CAD packages.
Directly in mechanical engineering, specialized packages and various add-ons of more common and common design systems, such as Autodesk AutoCAD, ZwCAD, BricsCAD, are used. Let's consider some of them.
AutoCAD Mechanical has the full functionality of the standard AutoCAD system, but at the same time provides additional features for design in the mechanical engineering field. For example, there are additional features for creating machine parts, parts of the "body of revolution" type. An extensive library of standard parts is available to designers. The creation of individual components of mechanisms can occur automatically.
A special edition of AutoCAD Electrical helps automate common tasks in the design of electrical control systems, thanks to a special set of software tools and legend libraries.
For those who focus on the development of mechanical and electrical systems, a special version of the Autodesk Inventor Series package called Professional has been developed. Allows you to increase work efficiency, control and simplify documentation.
Another variation of this software package is the Simulation Suite. It is intended for machine-building design of three-dimensional solid products. Allows you to evaluate the performance and strength of the designed components at the drawing stage.
If the task is not only the effective creation of new products, but also the modern management of a machine-building enterprise, then it is possible to introduce the TechnologiCS package, which was developed specifically for machine-building plants. Allows you to structure and accompany business processes typical for these enterprises (product development and modernization, production planning, production management).
The domestic computer-aided design system called T-Flex has already proven itself well at enterprises throughout the CIS. This is a professional software package, the next version of which includes five products at once: CAD directly, PDM-system for technical preparation of production, T-Flex Technology - for technological, T-Flex CNC drawing up a program for the machine for the production of a specific part, also in the system integrated environment for engineering calculations.
If we talk directly about T-Flex CAD, then its distinctive features are the wide possibilities for working with both solid objects and surfaces, which significantly increases the efficiency of the work of design engineers. In addition to standard libraries of objects and operations, the user can create and use his own, which contributes to the accumulation and application of production experience. Design elements can be applied automatically, while both domestic (ESKD) and international standards (ISO, DIN, ANSI) are supported.
The library of standard machine-building objects is constantly updated following the adjustments to GOSTs. It should be noted that it is distributed free of charge. Additionally, you can purchase libraries of elements of electrical circuits or machine tools.
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The main requirements for industrial production are to reduce the time to market, reduce its cost and improve its quality. It is impossible to fulfill these requirements without the widespread use of methods and systems of computer-aided design, technological preparation of production and engineering analysis (CAD / CAM / CAE-systems).
The history of the development of CAD / CAM / CAE systems in mechanical engineering is often divided into several stages.
At the first stage (until the end of the 1970s), a number of scientific and practical results were obtained, which proved the fundamental possibility of automated design of complex industrial products. The capabilities of the systems at the first stage were largely determined by the characteristics of the graphics hardware available at that time. Mostly used graphic terminals connected to mainframes, which were computers from IBM and CDC, or to PDP / 11 mini-computers. According to Dataquest, in the early 80s. the cost of one CAD-system license reached $90,000.
On second stage (80s), graphic workstations from Intergraph, Sun Microsystems with the SPARC architecture or workstations on DEC VAX computers running Unix appeared and began to be used. By the end of the 80s. the cost of a CAD license has dropped to around $20,000. Thus, the prerequisites were created for the development of CAD / CAM / CAE systems for a wider application.
At the third stage (starting from the 90s), the rapid development of microprocessors led to the possibility of using workstations on personal computers, which significantly reduced the cost of introducing CAD in enterprises. At this stage, the improvement of systems and the expansion of their functionality continue. Since 1997, Wintel-based workstations have been on par with Unix-based workstations in terms of sales. The cost of the license has dropped to several thousand dollars.
The fourth stage (starting from the end of the 90s) is characterized by the integration of CAD / CAM / CAE systems with PDM design data management systems and other means of product information support.
It is customary to divide CAD / CAM-systems according to their functional characteristics into three levels (upper, middle and lower). In the 80s and early 90s, this division was based on a significant difference in the characteristics of the computing equipment used for CAD. The hardware platform for top-level CAD/CAM systems was expensive, high-performance Unix workstations. This technique made it possible to perform complex operations of both solid and surface geometric modeling in relation to assemblies of many parts. Low-level CAD systems were intended only for automating drawing work performed on low-end workstations and personal computers. As the performance of personal computers improved, it was possible to create relatively inexpensive systems with the capabilities of parametric and associative 3D modeling. Such systems began to be classified as mid-level CAD / CAM systems. Today, the division of CAD / CAM systems into CAD of the upper, middle and lower levels is still preserved, although it suffers from obvious fuzziness.
The design of mechanical products consists primarily in the design, i.e. in determining the geometric shapes of bodies and their relative position. Therefore, the history of design automation in mechanical engineering is connected with the history of computer graphics and practically began with the creation of the first graphics station. It was a Sketchpad station using a display and light pen, introduced in 1963 by I. Sutherland. Raster displays began to be used in the 70s. I. Sutherland later worked at ARPA, heading the department of information analysis and processing in this agency, and later became a professor at Harvard University
By 1982, Computervision, IBM, Prime, and others began to use solid modeling in their products, but methods for obtaining complex-shaped body models have not yet been developed, and there is no surface modeling. The following year, a technique was developed for creating 3D models with showing or removing hidden lines. In 1986, Autodesk releases its first CAD product, Autocad, a single-user version in C with support for the IGES format. In 1988, equipment was created for prototyping products using laser stereolithography based on data obtained in MCAD. Also in 1988, PTC pioneered model parametrization.
The development of computer graphics was determined not only by the capabilities of the hardware, but also by the characteristics of the software. It had to be invariant with respect to the hardware used for input and output of graphic information. Therefore, since the 1970s, considerable attention has been paid to the issues of standardization of graphic programs. The basic graphics system standard includes a functional description and specifications for graphics functions for various programming languages.
In 1977 ACM publishes the Core document describing the requirements for hardware-independent software. And in early 1982, the Graphical Kernel System (GKS) appears, which defines the primitives, segments and transformations of graphic data and became the ISO standard in 1985. In 1987, a variant of GKS-3D was developed with a focus on 3D graphics.
In 1986, a number of new standards are approved. Among them are CGI (Computer Graphics Interface) and PHIGS P (Programmer's Hierarchical Interactive Graphics System) - an ANSI standard that became an ISO standard in 1989. In 1993, Silicon Graphics proposed the OpenGL (SGI Graphical Language) standard, which is currently widely used .
These systems use graphic formats for data exchange, which is a description of the image in the functions of a virtual graphics device (in terms of primitives and attributes). The graphic format (metafile) provides the ability to store graphic information in a unified way, transfer it between different systems and interpret it for output to various devices. Such formats are CGM - Computer Graphics Metafile, PostScript - Adobe Systems "Language, GEM - GEM Draw File Format, etc.
The work on standardization was aimed at expanding the functionality of graphic languages and systems, including in them the means of describing not only the data of drawings and 3D models, but also other properties and characteristics of products.
In the field of design automation, the unification of the basic operations of geometric modeling has led to the creation of invariant geometric kernels intended for use in various CAD systems. The two most widely used geometric kernels are Parasolid (a product of Unigraphics Solutions) and ACIS (Spatial Technology). The Parasolid kernel was developed in 1988 and the next year became the solid modeling kernel for CAD/CAM Unigraphics, and since 1996 the industry standard.
In parallel, work was carried out to standardize descriptions of geometric models for data exchange between different systems at various stages of the life cycle of industrial products. In 1980, the IGES (Initial Graphics Exchange Specification) format appeared, which became the ANSI standard the following year. Autodesk has begun using the DXF (Autocad Data eXchange Format) format in its products. In 1984, a technical committee TC184 was created in ISO for the purposes of standardization in the field of industrial automation, and within it, a subcommittee SC4 was created to develop data exchange standards, where the ISO 10303 STEP (Standard for Exchange Product Model Data) group of standards was developed, including the language Express and application protocols AP203 and AP214.
Examples of top-level CAD/CAM systems are CATIA (Dassault Systemes), Unigraphics (Unigraphics Solution), Pro/Engineer (PTC). Products from these firms have been available since 1981, 1983 and 1987. respectively. In 1998, Chrysler demonstrates the ability to create a comprehensive digital vehicle model (design, assembly, and test simulation) using CATIA. EUCLID3 (Matra Datavision), I-DEAS (SDRC), CADDS5 (Computervision) were also among the top-level CAD systems in the 90s, but their development was discontinued due to the merger of companies.
So, in 2001, the Unigraphics Solution company merged with SDRC, which meant the gradual cessation of the development of I-DEAS and the use of successful solutions of the two systems I-DEAS and Unigraphics (UG) in new versions of the Unigraphics NX system.
Even earlier, the CADDS5 system was acquired by PTC (Parametric Technology Corp.). This company, headquartered in the United States, was founded in 1985 by Semyon Geisberg, a former professor at Leningrad University.
The best-known mid-range CAD/CAM systems based on the ACIS core are AutoCAD 2000, Mechanical Desktop, and Autodesk Inventor (Autodesk Inc.); Cimatron (Cimatron Ltd.); ADEM (Omega Technology); Mastercam (CNC Software, Inc.); Powermill (DELCAM), etc. Mid-level CAD/CAM systems based on the Parasolid core include, in particular, Solid Edge and Unigraphics Modeling (Unigraphics Solutions); SolidWorks (SolidWorks Corp.); MicroStation Modeler (Bentley Systems Inc.); Pro/Desktop (Parametric Technology Corp.); Anvil Express (MCS Inc.) and others. PTC is starting to use the Granite One geometry core it developed in 2000 in its products.
In 1992, Intergraph Corporation, one of the then leading manufacturers of CAD systems for mechanical engineering, decided to develop a new software product entirely based on the Wintel platform. As a result, at the end of 1995, the Solid geometric modeling system appeared. In 1998, Unigraphics took over the entire Intergraph division dealing with CAD for mechanical engineering. At the same time, Solid Edge is changing the ACIS geometry kernel to the Parasolid kernel. In 1999, the 6th version of Solid Edge appeared in Russian.
In 1993, the Solidworks Corporation was created in the USA, and two years later it presented its first Solidworks parametric modeling package based on the Parasolid geometric kernel. Solidworks has become one of the leading mid-range systems.
A number of CAD / CAM-systems of the middle and lower levels were developed in the USSR and Russia. The most widespread among them are Compass (Ascon company) and T-Flex CAD (Top Systems) and some other systems.
The Askon company was founded in 1989. It included a team of developers who had previously designed the Cascade system at the Kolomna Design Bureau of Mechanical Engineering. The first version of Compass for 2D design on personal computers appeared in the same 1989. In 2000, CAD Compass was extended to 3D design. In 2003, the 6th version of Compass and PDM-system Lotsman:PLM was released.
Pre-production automation in CAM systems was not as tightly tied to computer graphics hardware as design automation in CAD systems. Among the first works on automating the design of technological processes, the creation of the APT (Automatic Programming Tools) language in 1961 in the USA should be noted. This language became the ancestor of many other programming languages for numerically controlled equipment. In the USSR, G.K. Goransky created programs for calculating cutting conditions in the first half of the 60s. V.D. Tsvetkov, N.M. Kapustin, S.P. Mitrofanov and others developed methods for the synthesis of technological processes in the 70s.
In systems of engineering calculations and CAE analysis, programs for modeling fields of physical quantities occupy a central place, first of all, these are programs for strength analysis using the finite element method (FEM).
The finite element method was developed in 1950 by specialists working in the fields of structural mechanics and the theory of elasticity. The term "finite elements" itself was introduced in 1960 by R. Clough. In 1963, a relatively simple method was proposed for applying FEM to strength analysis by minimizing potential energy. Software and methodological complexes for analysis and modeling based on the FEM have appeared.
In 1965, NASA, in order to support projects related to space research, sets the task of developing a finite element software package. By 1970, such a package called NASTRAN (NAsa STRuctural ANalysis) was created and began to be used. The cost of development, which lasted 5 years, amounted to 3-4 million dollars. One of the companies involved in the development was MSC (MacNeal-Schwendler Corporation). Since 1973, MSC (since 1999 the company has been called MSC.Software Corporation) independently continues to develop the MSC.NASTRAN package, which has become a world leader in its product class.
In 1976, the DYNA3D complex (later called LS-DYNA) was developed for the analysis of shock-contact interactions of deformable structures.
The Ansys complex can also be attributed to the leaders of CAE programs. In 2000, using the multi-aspect simulation tools implemented in Ansys, the possibility of joint simulation of electromagnetic, mechanical and thermal processes in the design of microelectromechanical devices was demonstrated.
Adams, developed and developed by Mechanical Dynamics Inc., is considered the world leader among macro-level analysis programs. (MDI). The company was founded in 1977. The main purpose of Adams (Automatic Dynamic Analysis of Mechanical Systems) is kinematic and dynamic analysis of mechanical systems with automatic formation and solution of equations of motion.
For the design of systems whose functioning is based on the mutual influence of processes of different physical nature, the possibility of multidimensional modeling is of great importance. The theoretical foundations of multidimensional modeling based on analogies of physical quantities were considered by G. Olson (1947), V.P. N.E. Bauman in the 70-80s. The main provisions of multi-aspect modeling were later enshrined in the standard dedicated to the VHDL-AMS language.
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Bibliographic list
1. Apokin I.A., Maistrov L.E. The development of computers. - M.: Nauka, 1974. - 399 p. 2. Guter R.S., Polunov Yu.L. From abacus to computer. – M.: Knowledge, 1975. 3.
It is difficult to find engineering companies in the world that do not use .dwg files to store and exchange 2D and 3D CAD data. Twelve million users of dwg-based applications rely on a familiar environment that implements well-known concepts of model and paper space, views, database objects, blocks, grips for editing objects, and the command line. This environment is easily expandable and customizable with hundreds of third-party products, helping users speed up the design process and arrange drawings according to various national standards.
Users and businesses can choose from a variety of dwg environment implementations—available as AutoCAD, DraftSight, IntelliCAD, and several others. However, none of these software packages are suitable for designing complex mechanical products—such as machines and their components—because they lack important features typical of today's 3D mechanical engineering CAD systems.
Playing multiple instruments at the same time is not easy.
Another significant problem with mechanical engineering CAD comes from the fact that all of these systems offer history-based parametric 3D modeling. It is very difficult for engineers who have worked in 2D for many years to adapt to this 3D design method. After all, users of systems based on the history of construction operate with parameters that are used to generate geometry. This approach is fundamentally different from the usual two-dimensional drawing, where users directly manipulate geometric objects (lines, arcs, polylines, splines) by dragging these objects and changing their shape using "handles".
Complex design methodology is not the only disadvantage of history-based engineering CAD systems. Another problem arises when working with data created in other CAD systems - including those systems that are no longer supported - imported from these CAD systems directly or through neutral file formats. The fact is that the construction history cannot be translated from one format to another, because each CAD system uses its own unique set of 3D modeling functions - with different parameters and semantics.
To address the challenges of complex design methodology in history-based systems and the inability to edit imported geometric models in these systems, mechanical engineering CAD vendors have recently added "direct modeling" software products to their portfolios. But this led to the emergence of a new problem: how to set the constructive concept of the model in systems without a history of construction? A design concept is a set of rules that define the allowable changes to a model's geometry.
In history-based systems, the design concept is given by the design history itself, which is not the case in direct modeling systems. Therefore, traditional history-based systems cannot be replaced by direct modeling systems; the latter can only supplement the possibilities of the former.
Three different products with different user interfaces required for construction
As a result, most leading mechanical CAD vendors now offer their customers three different types of software products: parametric CAD for 3D design, direct modeling system for working with imported geometry, and 2D drafting system for working with .dwg files in a standard way. As a result, engineering companies found themselves in the unenviable position of having to buy licenses, implement, organize technical support, and train employees on three different design software products. And while this extra cash burden may not be a problem for large companies, it certainly doesn't sit well with small-to-medium sized companies with tight IT budgets.
Bricsys Solution
Is there a way to stop the unhealthy growth of IT spending on CAD for engineering companies? Is it possible, on the contrary, to reduce these costs several times over? Is there a single software product for 2D drafting and 3D modeling in the familiar dwg environment? Is it possible to design a design methodology that combines the advantages of systems based on history of construction and direct modeling, but without the disadvantages of each of these approaches?At Bricsys, we believe there is a solution! Moreover, we are consistently implementing it.
2002
Release of BricsCAD, a full-featured .dwg-based CAD system that is fully compatible with AutoCAD through its command set and other end-user features. BricsCAD is also a powerful platform for third-party developers who can easily port their applications built using a wide range of standard programming interfaces (APIs). To date, third-party developers have ported several hundred applications to the Bricsys platform in the field of architectural and construction and mechanical design, GIS, data exchange and other specialized areas. Over three hundred of them are available in the online store at www.bricsys.com.2011
3D direct modeling in BricsCAD. Our approach is called variational direct modeling and uses three-dimensional geometric and dimensional constraints (dependencies) to define the constructive concept of any geometric model, whether developed in BricsCAD or imported from other CAD systems. Automatic design concept recognition makes it much easier for users to become familiar with the world of 3D design compared to other 3D CAD systems.
Variational Direct Modeling is an easy way to create and edit complex 3D parts in BricsCAD
2012
Modeling assemblies in BricsCAD. There is no longer a need to use expensive CAD software to assemble complex products from 3D parts, including a library of 30,000 standard parts. With 3D geometric and dimensional constraints (constraints), users can easily position 3D parts and assemblies in the way they want and use the remaining degrees of freedom in the model to analyze the forward and inverse kinematics of any mechanism that their imagination can create.
Modeling of assemblies and analysis of the kinematics of the designed mechanism in BricsCAD
In our next posts, we will take a closer look at the key features of BricsCAD Platinum for mechanical design and share our plans for the development of this product.
Currently, a large number of CAD / CAM systems and specialized applications for them are presented on the Russian market. There are no problems with the acquisition of such programs. But in the process of designing, manufacturing a part or testing a technology, a specialist needs a universal tool with which he could quickly solve all the problems that arise. Our goal is to introduce you to the features of the software and the necessary applications that will be useful to you for foundry, forging and machining and machining processes, how to use this software effectively and quickly get results from it.
All the programs that we will talk about are divided into two types: general-purpose programs and special-purpose programs. All programs require a graphics core for their work, the role of which in this case is played by AutoCAD. Why did we choose AutoCAD as the graphics core? Because AutoCAD is a well-made program that has been sold worldwide for a long time (currently over a million copies of this program have been sold), it has more than 4,000 applications for various fields of knowledge and AutoCAD is currently the standard for graphics systems running on personal computers.
What can AutoCAD be used for? It can be used to perform design and construction work in various fields of mechanical engineering, construction, cartography and architecture to work with flat drawings and three-dimensional models of product designs, buildings and even factories. In addition to AutoCAD, Autodesk offers many specialized general-purpose programs that extend the capabilities of AutoCAD.
This is an AutoCADDesigner program that allows you to create computer models of 3D parametric products, including associativity of all sizes, flat images and 3D solid computer models.
AutoSurf allows you to work with complex surfaces and thin shells using spline modeling using NURBS mathematics.
Autodesk MechanicalDesktop supports end-to-end 3D parameterization and allows you to design and build complex 3D solid and 3D product models.
AutodeskWorkCenter is designed to bring together a large number of people to work on a large project.
AutoCAD and other products from Autodesk are general purpose products. This class of programs also includes programs from Intermech, Cimlogic and VibrantGraphics. VibrantGraphics-SoftEngine4 and SoftPoint are drivers that are designed to speed up AutoCAD-based systems by 25 times. SoftEngine has the functions of instantaneous zooming and panning without image regeneration, allows you to quickly tint, cut and rotate tinted three-dimensional objects and structures in real time, as well as have many other useful features. Intermech and Cimlogic software allows you to very efficiently and quickly create flat drawings of individual parts, assemblies and products as a whole. The software includes modules for calculating chain and belt drives, pulleys and cams, springs, shafts, for calculating moments of inertia and other product characteristics, including complex kinematic calculations. The software of these companies has modules for working with spatial products made of sheet materials and a program for working with three-dimensional databases of standard parts and fasteners. The program contains many commands and modes that greatly simplify the process of drawing and reduce the time of making all types of drawings.
Special-purpose programs include programs from FlowScience, Rebis, SofDesk, Surfware, GTX and programs developed by Russian Industrial Company specialists for foundry and forging and pressing production.
GTX--GTXRasterCAD software is designed for quick and easy translation of any documentation, including complex and rich drawings from paper into electronic form. The program works like an AutoCAD application and allows you to load a scanned drawing directly into the AutoCAD environment. Image editing can be done using GTXRasterCAD specific smart functions or AutoCAD menu commands. GTX programs recognize and vectorize not only the drawing, but also the text that was contained in the drawing field. The program contains functions for cleaning the drawing from the "garbage" that appears in the drawing field when scanning old and low-quality design documents.
Rebis software is designed for plant design and includes programs for designing piping systems, designing and arranging equipment, designing load-bearing structures, modules for performing verification calculations of individual elements and the entire project as a whole.
With the help of SofDesk software, you can solve all the problems with automating the design of building structures, calculating the main elements of this project, and obtaining the necessary regulatory documentation.
FLOW-3D software from FlowScience Inc. will allow you to simulate the processes of mass and heat transfer in a three-dimensional setting. Currently, this software package is used in the design of aircraft and marine vehicles, in the automotive industry, for the design of cooling and ventilation systems, for the design of oil and gas pipelines, in rocket science, in the design of technology for foundry and metallurgical processes, for plastic molding and in other industries industry.
The software developed by the specialists of this company is used to design casting technology, design molds for casting metals and plastics, to obtain the initial shape of a workpiece for cold sheet stamping during bending, drawing and molding technological operations, to obtain an optimal cutting pattern for stamped parts. For this, the programs "Technologist", "Designer" and "AutoSheet" are used.
Software from Pathrace Inc. is intended for computer simulation of machining processes, quality control of the resulting product and obtaining a control program for 2 ... 5 coordinate CNC machines. The program takes into account the characteristics of the equipment used by the user. The EdgeCAM program allows you, using a computer model of your product, to go through all stages of its processing, show the places of possible defects or non-compliance with the requirements for the product you want to receive, and help you create the best control program to obtain this product with guaranteed quality on your equipment.
Due to the fact that EdgeCAM was developed by specialists with extensive experience in the field of mechanical processing, the program has a friendly interface and is focused on the use of process engineers involved in the development of technology for obtaining parts by cutting on CNC machines. The EdgeCAM program is made on a modular basis. It includes "Geometric Modeler" - a program for creating a spatial geometric model of a workpiece; a program for visualizing the geometry of the processed object, the process and results of processing the product; programs for checking and identifying possible defects in the process of computer simulation of product processing; a product processing simulator and a postprocessor that supports several hundred racks for all major types of CNC machine controllers. Also, the program includes a database with blank materials, tool materials and the range of tools used. The program has the following features:
Simultaneous multi-axis processing -- EdgeCAM supports simultaneous processing of three, four and five axes of coordinates.
Machining Multiple Surfaces - An unlimited number of cut and uncut surfaces can be machined in a single operation, eliminating the need for separate NC programs for each surface. This allows you to rough or finish NURBS, cut NURBS and parametric surfaces in one step with a ball or end mill.
Undercut Prevention - EdgeCAM's multiple surfacing feature checks the tool on all sides to avoid undercutting and protect the tool neck.
Graphical modeling of the tool and its paths - visualization of tool paths is performed in real time as they are generated. In addition to the existing extensive tool library, special tool and spindle shapes can be created to display them on the screen in order to check their position relative to the part, and much more...
Using the EdgeCAM program will allow you, using computer simulation of machining processes, to completely eliminate or significantly reduce the percentage of rejects in the manufacture of complex fittings, molds or their elements, metal models for casting, dies and their elements, etc.