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Introduction To CAD And CAE

Both Computer Aided Design (CAD) and Computer Aided Engineering (CAE) have now become an integral part of manufacturing. The ‘traditional’ way of creating engineering drawings – using drafting tools – is now passé. The traditional way was tedious and lengthy. Typically, many iterations (read: time) passed before the draftsmen really understood what the designer wanted, and the entire process was very time consuming. The introduction of CAD revolutionized the design process, and CAE took it one step further. Let us now understand the synergy between CAD and CAE, and how they differ from each other.

Difference between CAD and CAE
There are many stages involved the product manufacturing cycle. The first is, of course the concept of the product. Let us take the example of a simple product like a cup. Cups come in different sizes and shapes. Manufacturers always attempt to come up with attractive and innovative designs. An artist then comes up with a new design, using appropriate CAD software like PTC Creo, CATIA, Solidworks, etc. However, it is a different ballgame altogether to translate the design into a utilitarian product. This is where CAE comes in. After the designing team hands over the CAD drawings to the engineering team, they assess the design from an engineering perspective. A cup is utilized to consume hot or cold liquids. It must therefore be able to withstand temperature fluctuations. The handle should be engineered in such a way that it is able to withstand the weight of the liquid without breaking. Furthermore, the entire weight of the cup and the liquid inside must be optimum, so that the user has no difficulty lifting the cup. As you can see, CAD and CAE play a different role in manufacturing, even for a simple object like cup. Simply put, CAD is the basic step in the manufacturing of an object, followed by the second step which is engineering analysis or CAE. When it comes to design complex objects or parts, the differences between CAD and CAE are more obvious. Many times, what designers feel is aesthetic may not be feasible functionally. When it comes to producing objects (like an aeroplane), this difference is glaringly obvious. While it is relatively easy to conceptualize an aeroplane using CAD, it is more difficult to make it really fly, and this is where CAE is useful. In such cases, both the design and the engineering teams need to proceed iteratively till they reach an optimum balance between what the designers want and what the engineering team can achieve.  CAD allows designers to express their designs by drawing, building and describing a model and its characteristics, while CAE enables engineers to analyze, test and improve that model.

Of the two, CAE is the more intricate than CAD, as it involves many engineering principles. While CAD simply involves design, CAE involves actually simulating the product’s behavior in real life. CAD is used to help the users create and modify the graphic properties of a design, using either 2D or 3D drawing, defining parameters like tolerances and dimensions. CAE tests the model for parameters like temperature, pressure, component interactions and applied forces. That said, both CAD and CAE require a lot of practical training before it can be put to use. Typical software used for CAE simulation includes Ansys, Altair HyperWorks and HyperMesh among others. Simply put, a major difference between CAD and CAE is that CAD software designs while CAE software analyzes. Another difference between CAD and CAE is that CAD models must aim to represent a design lucidly and in detail, while CAE strives to solve the engineering problem determined by the boundary and load conditions set on a model.

Like has been stressed above, CAD involves 2D or 3D rendering of an object or a component, while CAE involves engineering analysis of it. Here is what CAE involves:

1.    Static and dynamic analysis
2.    Buckling analysis
3.    Thermal analysis
4.    Fatigue analysis
5.    Optimization
6.    CFD analysis
7.    Crash analysis

Since CAE inherently involves simulation and prototype creation of a real life model, it says everyone time and money, as modern CAE software like Ansys, Altair HyperWorks and HyperMesh have the capability to validate the authenticity of the CAD drawings of that model.

Training in CAD and CAE
Traditional CAD drawing is almost non-existent now; replaced by CAD software like Creo, AutoCAD, etc. These software are powerful tools. To master them is not easy; especially if you want to make a career in the field of CAD. Proper training is needed to grasp the nuances and leverage their power. CAD finds use not only in manufacturing industry, but even in other fields like structural design and architecture. The 3D walk-throughs that builders display are based on the inputs of CAD drawings. The same is true of CAE software. Most reputed CAE software offer different modules that focus on a specific engineering parameter like thermal analysis, pressure analysis, fatigue analysis, etc. Most of them are based on Finite Element Analysis, a numerical method that offers a means to find approximate solutions to complex mechanical engineering problems. Like CAD, these CAE software suites are difficult to master as well. There are many training institutes today that give practical CAD and CAE training. The better ones not only impart theoretical knowledge, but also give hands-on training that gives students a boost in their career. These institutes are not the avenues for CAD and CAE training; there are various online resources – both free and paid – that offer courses. However, the main drawback of online CAD / CAE training is that the students do not get practical experience. Nothing beats practical, hands on training in CAD and CAE from experienced teachers! Even the companies that develop these software are aware of the necessity of quality, real world training. They have collaborated with quality CAD and CAE training institutes to educate students. In India, industrial cities like Pune, Hyderabad and Bengaluru are at the forefront in having such institutes that are officially recognized by companies like Dassualt, PTC and Altair.

To summarize, CAD focuses on the conceptual aspects of an object / component, while CAE analyzes the design from an engineering perspective and translate the concept into a viable product. Though they are different, both CAD and CAE software of today are extremely advanced and require training to bring out the best in them.

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