The following is a detailed introduction:
CAD is computer aided design (CAD), and its concept and connotation are constantly developing. 1June, 972, international federation for information processing gave the following definition at the "Working Conference on CAD Principles" held in the Netherlands: CAD is a technology, in which people and computers, as a problem-solving group, combine together and cooperate closely to give full play to their respective advantages, thus making their work better than each other's, and providing the possibility for comprehensive cooperation in applying multidisciplinary methods. CAD is a general term for engineers and technicians to design, draw, model, analyze and write technical documents for products and projects with computers as tools.
According to different models, CAD systems are generally divided into two-dimensional CAD and three-dimensional CAD systems. Two-dimensional CAD systems generally regard products and engineering design drawings as a collection of geometric elements such as points, lines, circles, arcs, texts, etc. . Any design expressed in the system becomes a geometric figure, and the mathematical model it depends on is the geometric model. The geometric characteristics of these elements are recorded by the system. Two-dimensional CAD system generally consists of graphic input and editing, hardware interface, data interface and secondary development tools.
CAD is a product of Autodesk company.
The core of 3D CAD system is the 3D model of product. Three-dimensional model is to represent the actual shape of the product into a three-dimensional model in the computer, which contains all kinds of information about the points, lines, surfaces and bodies of the geometric structure of the product. The description of computer three-dimensional model has experienced the development from wireframe model, surface model to solid model, and the geometric information expressed is more and more complete and accurate, which can solve a wider range of "design". Among them, the wireframe model only uses the edge line of geometry to represent the shape of geometry, just like the shape built by wireframe, there is no information such as surface and volume in the model. Surface model is to construct the model by using the outer surface of the geometric shape, just like covering a layer of skin on the wireframe model, which makes the geometric shape have a certain outline and can produce effects such as shadow and blanking, but the model lacks the concept of geometric volume, just like an empty shell of geometric body. When the geometric model develops to the solid model stage, the closed geometric surface forms a certain volume, forming the concept of geometric body, just like filling something in the middle of geometric body to make it have the characteristics of weight and density, so that the collision and interference between two geometric bodies can be checked. Because the model of 3D CAD system contains more actual structural features, users can better reflect the actual product structure or manufacturing process when designing product structure with 3D CAD modeling tools.
At present, 3D CAD system has become the mainstream tool for enterprises to carry out product innovation design. 3D CAD system has developed from early solid modeling to feature modeling and constraint-based modeling.
CAD system is widely used in machinery, electronics, automobiles, aerospace, molds, instruments, light industry and other manufacturing industries. Three-dimensional CAD system provides powerful functions in parts modeling, assembly modeling and welding design, mold design, electrode design, sheet metal design, etc., and realistic display and surface modeling functions are also very powerful.
At present, the high-end 3D CAD systems mainly include UG NX, CATIA and Pro-E, while the mainstream 3D CAD systems in the middle end mainly include SolidWorks, SolidEdge and Inventor. Domestic 3D CAD systems include Solid3000 and CAXA entity engineers. The popular 2D CAD systems in China mainly include AutoCAD, CAXA, Zhongwang and Chen Hao.
Based on 3D CAD system, many CAE/CAM systems support product design/simulation and manufacturing.