Computer aided design refers to the use of computers and their graphical devices to help designers carry out design work.
It is called CAD for short. In engineering and product design, computers can help designers to take charge of calculation, information storage and drawing. In design, it is usually necessary to use computers to calculate, analyze and compare a large number of different schemes to determine the optimal scheme; All kinds of design information, whether digital, literal or graphic, can be stored in the computer’s memory or external memory, and can be quickly retrieved; Designers usually start with sketches, and the heavy work of turning sketches into working drawings can be done by computers; The design results automatically generated by the computer can be quickly displayed in graphics, so that designers can judge and modify the design in time; The computer can be used to process graphics data related to editing, zooming in, zooming out, translation and rotation of graphics. CAD can reduce the labor of designers, shorten the design cycle and improve the design quality
How to draw arc in cad? In the design of CAD plan drawings, an arc is defined as a part of the circumference. CAD arcs are widely used in many building models, such as circular structures or decorations in highways, railways, water conservancy, electric power, building buildings, and municipal garden projects. Drawing arcs with CAD tools can help users deal with various building models more efficiently. At the same time, there are many skills in drawing arcs in CAD tools, The following are the efficient methods and techniques brought by BE-CU.COM. How to use cad?Those who are interested might as well come and have a look!
Tool 1: Auto Cad
- First, open the CAD drawing software that we installed on the desktop in advance. If you need to create an environment for the first time, wait for a period of time to create a new blank cad file to enter the drawing interface. Click the [Arc] function drop-down of the menu column to select the [Three Points] option, as shown in the figure;
- Step 2: specify the starting point of the arc according to the command line prompts, click the left mouse button to snap to the corner of the lower left corner of the triangle, and then specify the second point of the arc, that is, the vertex of the triangle. Click the vertex to snap
- Finally, specify the end point of the arc according to the command prompt, click the corner at the lower right corner of the triangle, and a standard compliant cad arc is completed.
Tool 2: Fengyun CAD Editor
- The first step is to install the application of Fengyun CAD Editor that we downloaded on the official website in advance on the desktop of the computer. Double click the shortcut to open it directly. For the first time, open the drawing environment that needs to create cad drawings. You can safely wait for a while to create a new blank cad file;
- Step 2: select the Editor category in the top menu column, select the arc figure in the Draw column to draw, click the left mouse button to determine the first endpoint of the arc, drag the mouse and click the left mouse button again,
PTC/ProE guides CAD into a new world of parametric feature design
1. Industry is eager to make 3D CAD practical
Parasolid and Medusa are voxel assembling systems that assemble cubes, cylinders and cones into mechanical parts in a way similar to building blocks. At the time, CAD software provided three-dimensional design tools is wireframe modelling, allowing designers to draw on a two-dimensional construction plane, the computer automatically transformed the two-dimensional construction plane into a three-dimensional product model space, and then manually masked the wireframe to produce a complete three-dimensional surface model. At the same time, as early as 1978 MIT Professor David Gossard put forward the idea of designing products with functional form elements, for example, the drive shaft in machinery is composed of shaft body, threaded segment journal, receding tool groove, flange, keyway, etc. Using the knowledge of the product’s functional structure, reasoning can be done through feature semantics to guide the intelligent design of the product and CAD/CAPP/CAE/ CAM integration. The theoretical study of feature design was then rapidly demonstrated after 1985, and a variety of experimental systems were developed, Mochizi. In this situation SamuelGeisberg stood out and proposed the development of parametric feature modelling, and set up ParametricTechnology to launch the Pro/Engineer product, which set a new convention for CAD three-dimensional design.
2. The achievements of Samuel Geisberg
CAD is a high technology and each of its major advances is supported by the innovative thinking and research of representative figures. 1963 IESutherland’s SKETCHPAD interactive drawing system PhD thesis led to the development of the CADAM system, 1962-1968 SACoons and PEBézier’s surface theory played a seminal role in CAD surface modelling. ICBraid’s work in 1970-1979 ensured the success of solid modelling with the boundary representation method. However, Braid only considered quadratic regular surface voxels in his algorithm and did not bother with free-form surfaces, which were much more difficult to handle mathematically in terms of intersection and clipping.
Samuel Geisberg was born in the Soviet Union and worked as a professor of mathematics at Leningrad University before coming to the United States in 1974 at the age of 37, working first at CV and then moving to lead the solid modelling group at Applicon. His reformist ideas were not accepted by Applicon and with funding from Adage he formed PTC in 1985 and developed an experimental system on a PC/AT machine, securing a further $3 million investment. pro/E caused an audience sensation when it was first demonstrated at AutoFACT in November 1987. pro/E developed the idea of 3D wireframe design The idea is to first establish a datum plane, sketch a two-dimensional sketch on the datum plane, and use the sweep method to extend the two-dimensional contour lines into a three-dimensional form. The planes are changed in turn, and the shapes are generated as far as possible by explicit operations, avoiding the need to search for intersections and cuttings on all sides. The overall goal of Pro/E is to integrate surface, solid and parametric feature design into one, allowing complex parts and assemblies to be constructed at will and to modify the design. It is easy to modify the design. The development of Pro/E was not always easy, but the greatest difficulties were in achieving rapid, reliable and efficient solutions to surface intersection and clipping operations in set operations and geometrical constraints in parametric sketching, which required mathematicians to delve deeper and work hard to break through certain technical keys. He was able to overcome all kinds of criticism and make Pro/E universally accepted, setting a new milestone for the development of CAD technology.
3、The CAD industry calls for the full commitment of mathematicians
CAD must be based on solid mathematical theory, but it is not enough to rely on mathematical theory alone; it is also necessary to turn the theory into a comfortable software product and to develop new processing techniques for the various special situations in engineering applications. There are many examples of this. The Department of Engineering at the University of Cambridge in the UK has been using Bézier surfaces since about 1977 to develop a DUCT design and processing system that uses a spine and a set of profile lines perpendicular to the spine to construct complexly shaped turbine pump housings, plastic bottles with handle holes, car exhaust pipes and other ingenious ideas. John Owen, who founded D-Cubed in 1989, developed the geometric constraint solving software DCM, which developed from 2D to 3D and later added geometry bumping and gap detection. 130 CAD companies have signed up to incorporate DCM components into their products since 1990. Geomagic, a US company founded in 1996, specialises in reverse engineering geometry modelling and measurement verification software, founded by Austrian mathematician Herbert Edelsbrunner, and ranks first in its industry in terms of performance, with a number of patented algorithms. In addition to this, all successful CAD companies have employed senior mathematicians to work on in-depth software development and maintenance. Many problems seemingly simple but difficult to deal with in CAD applications have to be tackled in a different way and research is increasingly going deeper. However, these research results are never published in the public domain due to the fierce competition between companies. Only the best companies with a high market share are able to extract sufficient funds for research and development from their rich earnings to keep the best people in place and maintain the continuous high speed of product development.
4. Venture capital is another necessary condition for the growth of PTC
Academic research in the United States is flourishing, and it is based on a solid foundation of industrial applications. In mechanical engineering and computer departments, academic research in universities is 5-10 years ahead of industry. As soon as you do research that is very viable and represents the direction of society, someone comes along and helps you commercialise it and get money from Wall Street to take the product and company public within three to five years. this is how Cisco came about, this is how Google came about, and countless other companies came about. 
Electrical CAD is CAD software used in the electrical design field to help electrical engineers improve the efficiency of electrical design and reduce duplication of effort and error rates.
Professional electrical CAD software such as Leach SuperWOEKS is well regarded and widely used by electrical engineers because it is tailored to the needs of electrical design and is specifically tailored to the electrical profession, helping electrical engineers to achieve intelligent and fast electrical CAD design work.
1. Objectives and scope of electrical CAD systems
The electrical design of mechanical products includes the design of circuit diagrams, wiring diagrams, installation diagrams, junction boxes and cabinets as well as push-button stations, which are not isolated from each other but are interlinked. The objective and scope of the electrical CAD system is to establish an electrical CAD system that is adapted to the above functional requirements, ensures design quality, improves efficiency, shortens the design cycle and reduces manual labour, including the design of circuit diagrams, wiring diagrams, installation diagrams, junction boxes and electrical cabinets, and push-button stations.
2. The proposed design method of the electrical CAD system
Firstly, according to the characteristics and problems of electrical design in mechanical product design, a retrieval design method must be adopted to solve the problem of large design freedom and irregular design in electrical design, to standardise the selection of electrical components, to standardise the function and performance of electrical design, to meet the requirements of reducing product cost, and to solve a large amount of repetitive labour in electrical design, to shorten the design cycle in order to shorten the The purpose of the delivery period, the designer from a large number of repetitive work to free, to engage in creative work.
In the traditional electrical design of mechanical products has accumulated a large amount of information, can be organized, summarized by the combination of components for a certain function of common components or small parts, which is the basis for the establishment of common components or small parts of the electrical CAD system graphics library, database, but also for the further development of modular design to create the conditions.
Furthermore, through the analysis of some of the components in the electrical design of mechanical products, it is found that not only their shape is more standardised and similar, but also the size is more standardised, with many varieties and specifications, according to which these conditions can fully adopt parametric design methods.
In order to improve the level of electrical design, on the basis of the retrieval design, the experience of electrical design is summarised so that it forms the design rules, and the system is upgraded to an expert system by using the various databases and graphic libraries that have been established by the retrieval design.
3. Functional design of the electrical CAD system
To achieve information sharing and meet the above objectives, the system must have the following functions.
- -establishing a uniform electrical design drawing surface, drawing width, component labelling, and title bar format.
- -Establish a shared database and graphics library, including a library of electrical graphic symbols according to national standard GB4728 combined with industry and enterprise standards.
- -Provide users with the ability to create and expand graphic symbol libraries
- -Provide quick, easy and flexible search functions for the graphic symbol library in the system, including querying, calling, inserting, deleting, etc.
- -Provides the function of marking graphic symbols and text respectively, automatically identifying different component graphic symbols when marking graphic symbols, and extracting the corresponding marking content to prepare for the generation of wiring diagrams
- -Can automatically determine the corresponding coordinate positions of contacts and coils on the drawing, reducing manual search labour, improving work efficiency and avoiding errors that can easily occur with manual search.
- -The ability to call up drawings completed by mechanical CAD to complete the design of electrical installation diagrams.
- -The system can read the information in the circuit diagram and generate the wiring diagram semi-automatically.
- -The system can read the library of standard and outsourced parts, mark the installation diagram and generate a list of standard and outsourced parts or a list of standard and outsourced parts.
- -The design of the junction box applies parametric design methods, the junction box shape is more standardised, the size and specification parameters can be serialised, the best results are achieved by using parametric design methods.