What is the Difference Between CAD and CAE?

 The main goal of this article is to clarify the distinction between CAD and CAE. However, let us first define CAD precisely.

CAE AND CAD

CAD: What is it?

Before computer-aided design (CAD) was developed, engineers used manual methods for drawing and calculating. That would be seen as a struggle in the modern day. The engineers had to simplify their product in order to calculate how it would behave in the event of external forces being applied, and they were only able to draw three distinct views on their sheet of paper. Engineers could now create precise 3D models thanks to the advent of computer-aided design (CAD) software. These 3D models can now be examined with computer-aided engineering (CAE) software thanks to additional technological developments.

CAE VS. CAD TOOLS

Making Calculations Automatically vs. Manually

Students must first learn how to solve mechanical problems in order to become qualified mechanical engineers. In this case, our mechanical issue is the requirement to ascertain the impact of wind on Munich's Olympic Tower.

We start by making the model simpler. Specifics and elements of the tower (such as the eatery and antenna) that may not be required for a preliminary mechanical computation will be removed. 

Initially, we sketch the tower roughly—in our case, just a single line on paper. In order to calculate the momentum at the base of the tower, we estimate the wind as a constant force at the tip of the tower. The wind force multiplied by the tower's height would be the only equation.

This is a very simplified model. Everyone, even the person in charge of the project's success, is aware that the situation is actually far more complex than that, and they would prefer a more advanced analysis of the issue.

Arguments against our simple approximation include:

1. The Olympic Tower is a complicated three-dimensional geometry rather than a two-dimensional line sketched on paper.
2. The wind is a dynamic force that produces turbulence and other effects rather than a single, steady force.
3. We make use of computer-aided engineering (CAE) power to compute this.

Comparing CAD and CAE

The Distinction In between CAE and CAD

Computer-aided design, or CAD for short, is the process of visualising a product idea on a computer. Computer-aided engineering, or CAE for short, is the analysis of the designed visualisation. To put it briefly, CAD is used for product design, whereas CAE is used for testing and simulation of the same product.

Clearly, there are benefits to using computers in design over more traditional methods. The following are some of the primary advantages of 3D CAD software over 2D drawing:

• The object can be made into a three-dimensional model. The shape and properties of the designed geometry are easier for engineers and production workers to understand. Furthermore, without being seen in three dimensions, some geometries can be incredibly complex, challenging, or even impossible to understand correctly. 

• Because the software recalculates the product after each modification, making changes to the geometry is very simple. Additionally, the CAD programme finds and warns you of any geometry mistakes that could, for example, result in a collision between moving parts.

• The ability to convert a CAD model into a mesh and simulate it for analysis and testing is perhaps the most significant benefit. 

Each of these advantages may contribute to lowering a product's marketing expenses and time to market.

The Difference Between CAD and CAE: The Meshing Process

Munich's Olympic Tower mesh made with SimScaleNow let's return to the main topic: what distinguishes CAE from CAD? The models utilised by CAD and CAE software appear to be nearly identical at first glance. But upon closer examination, it becomes clear that they are very different from one another. Though mathematically speaking, they are not very similar, even though they both have the product's shape.

To create a three-dimensional geometry, geometric elements can be assembled in a variety of ways. CAD models are most likely created as a collection of bodies or volumes with parameters like the real material's density. A parametric model with a construction history is the model that is most frequently used for CAD modelling. This offers the benefit.

Pre-processing in a CAE environment turns the CAD model into a mesh. Generally, polygon meshes are made up of cubes, cuboids, or tetrahedrons. As such, one can legitimately compare a CAD model to a vector graphic, while one could characterise a CAE model as pixelated.

CAD VS. CAE

Calculation and Post-Processing

This clearly shows that you cannot just transform a CAD model into a CAE model. The modeling of spheres, for example, will be a problem you will face. It is impossible to do this with volumes that have corners, but if the single volumes of the mesh are small enough, it can be a good approximation.

After the pre-processing is complete, the calculation starts. This differs according to the problem you need to solve and the type of simulation, such as finite element analysis, computational fluid dynamics, or thermal analysis.

In the previous example, after having designed the tower with CAD, a finite element analysis would be used to calculate the forces of the wind affecting the Olympic Tower.

After this step, post-processing has to be carried out to visualize the solution of the analysis. The visualization of the Olympic Tower looks like this:

Because of the limited computing power, the engineer will want to simplify the CAD model rather than attempt to process a perfect one. An engineer using a CAD model, on the other hand, aims to produce an exact representation of the model he has in mind. The estimates that are being given are extremely precise. Just consider the fact that the Olympic Tower's concrete column has tiny edges where the concrete planking was positioned rather than being perfectly round. The next steps are to create the mesh and set up the simulation after this is finished. You can look at this project to see the outcomes of the static and harmonic analyses that Learn More