91ÊÓÆµ¹ÙÍø

What Is CAD?
Knowledge

What Is CAD?

Today we are talking about CAD. Computer-aided design (CAD) is the use of computers (or workstations) to aid in the creation, modification, analysis, or optimization of a design.
Published: Jul 07, 2020
What Is CAD?

What is CAD?

Generally, there are two definitions of computer-aided design (CAD):

Computer-aided drawing:

Send all the data or sketches from the design to the computer system, and after processing, get the various engineering drawings required for manufacturing. The data on the engineering drawings generated by input or processing can be sorted and organized to form a database. In order to modify the drawing, it can also be exported in various forms for manufacturing and processing.

Computer-aided design:

Enter various specifications and conditions required by the design into the computer system, and use the design method organized in the database and the required data (such as material properties) to calculate or make decisions. Finally get various engineering dimensions and processing procedures and so on. Computer-aided design sometimes includes simulation. It is about to design the model (software model), and test its performance directly in the computer to check whether the design has a problem. Simulation can save the cost of physical testing, and can also help the best design, that is, calculate the best size and find the best processing program under the required specifications and conditions.

At present, the CAD system still focuses on computer drawing, drawing and solid simulation. Therefore, the CAD system mostly uses its drawing ability as a classification standard. The following briefly introduces the existing several systems.

Two-dimensional drawing (2D):

The software of the 2D system imitates the drawing of the projected image. Generally simple graphics, input from the CAD machine of the 2D system is not time-saving than drawing on the drawing table, but if some parts or components appear more often, CAD can save a lot of drawing time. Especially in the flexible production system, small-scale batch production, often used many standard parts, this time 2D system is a very effective tool. The drawing system stores all relevant data of all components and parts in the memory of the computer. In order to facilitate access and classification, the system includes a database. Newly built components or components can also be modified and stored by the original components or components.

If CAD machines of different brands are to be used in conjunction with each other, the interface is a big problem, even experts have a headache.

Choose two-dimensional drawing:

The same as 2D, it also expresses the graphics of the x-y plane. 91ÊÓÆµ¹ÙÍøever, it is more advanced than 2D, and you can choose the z coordinate position of the image to be represented. Users can choose different z-coordinates, that is, choose different projection planes (sections) for projection. At the same time, they can also change the direction of projection to get different angles of view. Projections of different z coordinates are often added with different colors.

Three-dimensional drawing (3D):

It can express three-dimensional graphics (outline ridge diagram) on a plane. 3D software can provide rotation of objects. (You must enter enough point and line data beforehand) Some 3D system software can calculate the volume, weight, moment of inertia and center of gravity of the object. (The system must have enough data to determine which part is hollow and which part is solid.)

The more irregularly shaped the object, the more ridges it has, and the more ugly the 3D graphics are. Therefore, the software of the 3D system must have a coloring method, so that different types of wires have different colors to achieve a clear visual effect. When actually looking at objects, some ridges are invisible, so these issues must be taken into account when designing the software. Different dots and lines must be hidden at various angles. Another software technique is called layering. When the configuration graph representing a plane is too complex, the configuration can be divided into several graphs for easy identification. For example, arrange all screw holes and screws on one drawing, and arrange other configurations on other drawings.

Surface Modelling£º

More advanced than 3D system. The soft model of the object is composed of the various surfaces that make up the outline. The system software can help coloring on different surfaces. Like the 3D system, objects can be viewed from different angles, and lines and surfaces that are invisible to real objects can be hidden. Of course, the color of each line and each surface cannot be affected by the rotation of the object. Some systems can calculate the luminosity and shadow of each position of the object (the position of the light source must be given first), so that the resulting picture is closer to the real object.

Solid Modelling£º

The body model can be said to be a physical prototype of the designer's software. The biggest difference between the volume model system and the aforementioned systems is the use of visual projection (perspective) rather than the parallel projection used in general engineering drawings. Therefore, the picture you see can be exactly the same as the actual object. The volume model system can still provide cross-sectional views at different positions. Although the 3D system can profile, it can only represent point lines, and there is no function of the surface model. The volume model is based on the position of the point and the properties of each position to establish the model, so you can calculate the physical quantities of the entity without entering additional data.

At present, this system is too expensive, so only the aviation industry uses this system. Because airplanes and space vehicles must save as much weight as possible, the design, simulation, and inspection requirements are very high, and they will not hesitate to invest huge costs.

The processing speed of the body model system is not fast. If you want to have the same processing speed as the 3D system, its computing power must be ten times stronger than the 3D system. The body model system has a big advantage, it can do physical fit (fit) experiments. After the components are designed, you can do assembly experiments on the terminal. The software structure of the body model is very suitable for the design of the simulation program. If the assembly is found to be incompatible, the design can be modified in time.

Published by Jul 07, 2020 Source : Source :

Further reading

You might also be interested in ...

Headline
Knowledge
The Birth of a Fabric: The Science and Craft of Textiles
Although fabric may seem like an ordinary item in our daily lives, its creation involves complex and highly precise processes. From cotton grown in the fields to synthetic fibers produced in factories, each raw material carries unique properties and purposes. Whether it¡¯s the light, airy touch of a shirt or the high protective performance of medical textiles, behind it lies a production chain that spans agriculture, chemistry, and engineering.
Headline
Knowledge
Exploring Major Types of Plastics and Their Properties
Plastic materials are indispensable raw materials in modern manufacturing. Based on their chemical structures and processing characteristics, plastics are mainly classified into two categories: thermoplastics and thermosets. Understanding the properties of these two types aids in material selection and product design, thereby enhancing manufacturing efficiency and product performance.
Headline
Knowledge
Analysis of Green Plastic Manufacturing
With the rise of environmental awareness and the global push for sustainable development goals, traditional plastics face increasing environmental pressure due to their challenges in decomposition and recycling. In response, the manufacturing industry is actively developing and applying eco-friendly plastic materials to build green manufacturing systems. This article explores the types, characteristics, and industrial applications of eco-friendly plastics to assist industry transformation and upgrading.
Headline
Knowledge
Key Parameters for Manufacturing High-Quality Plastic Products
Plastic materials are widely used across various industries due to their lightweight, ease of molding, and versatile properties. 91ÊÓÆµ¹ÙÍøever, different types of plastics exhibit distinct mechanical, thermal, chemical, and dimensional stability characteristics, which directly affect the final product¡¯s performance and service life. Therefore, understanding the performance indicators of plastics is fundamental to designing and manufacturing high-quality plastic products.
Headline
Knowledge
Dry Cutting vs. Wet Cutting: The Balance of Energy Saving, Cost, and Quality
In CNC machining, the choice of cooling method is not simply a technical preference but a multi-faceted trade-off involving cost control, machining quality, tool life, and production line stability. Both dry cutting and wet cutting have their advantages and limitations. To stand out in the fiercely competitive market, companies must shift from pursuing the ¡°theoretically optimal¡± to the ¡°contextually optimal¡± solution.
Headline
Knowledge
The Unsung Heroes of Cutting Tool Coatings: Performance Differences from TiN to DLC
In CNC machining, cutting tool coatings are a critical yet ¡°invisible¡± factor in boosting production efficiency and reducing costs. Although coating thickness is only a few microns, it significantly enhances tool hardness and wear resistance, optimizes heat dissipation, and improves cutting speed and machining accuracy. From classic Titanium Nitride (TiN) to advanced Diamond-Like Carbon (DLC) coatings, different coating materials not only offer varying hardness and heat resistance but also affect tool lifespan and machining adaptability.
Headline
Knowledge
Comprehensive Overview of Plastic Processing Methods: Mastering Key Technologies and Applications
Plastic products play an indispensable role in modern manufacturing, and various plastic processing techniques are crucial for achieving product diversity and efficient production. The following introduces five common and important plastic processing methods, helping readers gain a thorough understanding of their principles, features, and application scopes.
Headline
Knowledge
Fabric Knowledge Base: A Guide to Fiber Applications, From Beginner to Expert Selection
Textile fiber is the fundamental element that determines fabric performance and product suitability. Whether you are a designer, manufacturer, or consumer, understanding the unique characteristics of different fibers and their suitable applications is crucial for precise material selection and informed purchasing. This article will systematically introduce the applications of major natural and synthetic fibers and explain how blending them can overcome the limitations of single fibers, providing versatile functional solutions and helping you build a comprehensive knowledge base of textile applications.
Headline
Knowledge
What is Liquid Injection Molding?
Liquid Injection Molding (LIM) is a manufacturing process that involves injecting liquid silicone rubber (LSR) into precision molds, followed by heating and curing to form high-precision, complex plastic components. Compared to traditional thermoplastic injection molding, LIM offers superior accuracy and the capability to produce more intricate shapes, making it especially suitable for applications demanding high performance and reliability.
Headline
Knowledge
Precision Mold Development and Manufacturing: The Core Technology of Modern Plastic Production
Precision molds form the foundation for the quality and efficiency of plastic part molding. In today¡¯s highly competitive manufacturing environment, the design and fabrication of molds directly impact a product¡¯s functional performance and market competitiveness. Excellent mold development requires not only precise engineering design but also the integration of advanced machining technologies and rigorous quality control to achieve efficient and stable mass production.
Headline
Knowledge
The Magical Journey of Milk Tea
Pouring smooth, rich milk into robust black tea with a unique aroma, then stirring it all together, gets you a cup of milk tea. But do you really know what defines milk tea, and how it differs from the milk tea we enjoy today?
Headline
Knowledge
The Connection Between Textiles and Biomimicry: A Fabric Revolution Inspired by Nature
Lotus leaves after rain shed water droplets without a trace; delicate spider silk is stronger than steel. These are not coincidences but exquisite designs evolved by nature over millions of years. The textile industry is learning from this great designer¡ªnature itself¡ªthrough biomimicry, transforming natural wisdom into fabrics that perform better and are more eco-friendly.
Agree