Free Automotive Cad Design Course
Automotive Design & Marketing Management
As we have seen throughout the posts, the car design phase is divided into several steps. As we saw in the previous post, in the styling phase we also work with the computer, in addition to the sketches made by hand and with clay. Everything from an aesthetic point of view. Engineering begins in this phase.
3 - DIGITAL PHASE
In this phase, the sketches and models are transferred to the computer for further study and analysis. By now, it will be about 2 to 3 years since the project began. Although the development time of a project tends to be reduced, we have taken as a reference a classic project that takes five years. That includes different stages:
1 - Planning: The measures necessary to design the model are studied, the concept of the vehicle structure is planned according to the specifications.
2 - Development: The structure, the body of the vehicle and the interiors are designed at a technical level.
3 - Completion: This part is practically document management to be able to confirm with the suppliers that all the pieces can be manufactured. The choice of these providers is made by competition. The Cad are sent to them with the required tolerances and qualities, the terms and production volume. The suppliers will send their offer to the car brand. In addition, in this step the brand internally confirms the model specs. This is a little known internal procedure due to the secrecy involved.
4 - Decision: As in the Styling phase, the final solution must be approved by all technical departments. There are hundreds of designers working on a common solution with many different components, so at the end of each phase, those managers for each technical area will have to give their approval. Designers and engineers check possible interferences between the elements, and the manufacturing capacity of both the assembly and the elements separately. Once the board approves the project, we will go to the physical phase, this represents a huge disbursement for any car manufacturer, so the responsibility in this step is very high.
To work on car design in this phase, you will need to have a Bachelor of Engineering and manage a CAD program. Having a portfolio or having developed your own projects always helps, but it isn't essential as it happened in styling. There're also people with professional or technical training, and extensive experience in this field. So sometimes, it's possible to access this job without having any University degree. They will be able to specialize in performing parametric design with CAD, but they will not be able to carry out a simulation of the different components of the vehicle.
We start with the vehicle structural design, designing the different frames that make up the self-supporting chassis. This must obey certain technical parameters, such as torsional stiffness, or different resistance to impacts. Then the team will work on the design of the chassis: engine, suspensions, transmission, brakes, etc.
It's very important to plan the phases in advance to be able to overlap the vehicle structural design phase with the different departments that are working on the design of the different chassis components to save development time.
Once we have designed the chassis and the powertrain, the brand will give priority to the design of the functional components, such as the panels, seats or headlights. In the same way, all the design phases will overlap as possible to shorten design times and have the vehicle on the market without any delay. Multiple parts suppliers also come into play.
There are many CAD programs, we will see which are the main design softwares used in the automotive industry. In large manufacturers, a good percentage of Cad designs are outsourced, so sometimes you will carry out more document management than pure Cad design. After this step comes the simulation to predict the behaviors of the different components and assemblies. During the design of a car approximately 200,000 different simulations are carried out.
DIFFERENCE BETWEEN CAE, CAM AND CAD
Difference between CAE, CAM and CAD
If we are not used to it, it's very possible that we can get confused with these acronyms.
CAD: It's computer-aided design, in which the vehicle and its components are dimensioned and parameterized. Complex component assemblies are also verified.
CAS: It's a part of the CAD in which we design the surface, without a defined initial thickness. We mentioned it in the previous article to differentiate the design of a vehicle on an aesthetic level, from when we made the entire vehicle to work from an engineering point of view. In product design, a differentiation is not usually made. But in the automotive sector, CAS is part of a very different stage (Styling), and the rest of CAD is within the digital phase, for this reason we differentiate it.
CAM: Computer Aided Manufacturing. Broadly speaking, it encompasses the CNC (Numerical Control) to be able to machine a piece. For example, to manufacture a part by chip removal on a lathe or milling machine. It is linked to manufacturing and not so much to car design. Except for specific tasks of rapid prototyping, for example, making use of 3d printing. If your intention is to become a car designer, whatever phase it may be, you may be more interested in acquiring knowledge in Cad (Cas) / Cae than in Cam. Unless your interest is in 3d printing.
CAE: Computer Aided Engineering. All simulations are carried out, we will see it in detail below.
In summary: Let's imagine a desk table, for simplicity. The surface and aesthetics correspond to a surface-based design, that is, CAS. In the next CAD phase, we will give a real thickness to the table. But also, we will have to design the fastening systems with their screws, washers, ect. So we don't limit ourselves on aesthetics, but on providing a real solution and easy to fabricate it. At CAE we simulate the behavior of the table. In this case, we would make sure that it supports a certain weight, for example, if an 8-year-old child climbs on the table, the table should be able to support it for safety, although logically that isn't his function. In the CAM it would be designed how the wood would be cut and the orders would be transferred to the machine tool for its manufacture.
CAE IN AUTOMOTIVE
CAE in automotive
Cae is Computer Aided Engineering. It's essential to be an engineer to work in this field, or to have a compatible career such as physics or mathematics. Unlike the creative phases such as CAD vehicle modeling (CAS), you don't compete with artists and designers who come from different disciplines such as Architecture or Fine Arts. Nor is it necessary to have a design portfolio to work in this field.
If you are interested in engineering in car design, we recommend that you acquire some knowledge in a technical area. We will focus on mentioning the Cad / Cae systems, but there are a multitude of additional systems, especially in the electronics areas.
Author's note: Since I'm not an electronics engineer, but from the mechanical area, I will not focus on electronics. However, there is also a high demand for these specialists who master programs such as Simulink / Matlab. In fact, Cae also applies to many areas of electronic engineering.
The CAE is used to carry out all kinds of simulations. Some of them are the following:
Do you think there are too many different fields to learn at CAE? You are right, there are too many different areas. In fact, engineers specialize in only one of these branches, they don't try to master all of them since it would be impossible. The most common within simulation are perhaps FEM and CFD. Knowledge of plastic injection moulding or welding process simulation are also highly valued in the market. Increasingly, 3d printing expertise is gaining in importance in the automotive industry.
Any engineer with a high knowledge in only one of the previous fields becomes an ultra-specialized engineer and one of the most in-demand engineers. There are many more areas besides those mentioned here. Don't stay solely with these areas since CAD / CAE is as broad as engineering itself.
As a curiosity, some manufacturers don't accept calculations made only by computer, those calculations have to be supported afterwards by an exercise calculated by hand, when it's possible.
Computer simulation of a vehicle greatly reduces costs and design times, since the development of a new car model requires at least 50 prototypes to reach the final one. There are also more advanced prototypes, very similar to the final model. Of these, between 400 and 600 vehicles are manufactured. For these final prototypes, manufacturers allow themselves to recover most of the parts to offer them as reconditioned original spare parts. But the first prototypes, the vast majority ,will end up scrapped.
This represents a very high economic cost for the brand, of which end-consumers aren't aware. Each brand will determine how many prototypes to make, depending on their quality standards and their concern for fine-tuning the final product.
HOW MUCH DOES A PROTOTYPE COST?
How much does a prototype car cost?
This information is complex to obtain publicly, in addition, there are figures that cannot be published exactly, but there are price ranges.
These prototypes don't have the cost of a common car. The earlier the development phase of a vehicle, the more expensive the prototype. In the initial phase, these prototypes can cost between € 800,000 and € 1,000,000 approximately. In more advanced stages they range between € 120,000 and € 300,000. Let us bear in mind that in vehicle development the brand hasn't yet designed a tooling and an industrial mold for the model, hence its excessive costs.
Looking at these figures, we will try to produce the least number of prototypes in the initial phase, and we will try to manufacture them in the most advanced phases. Furthermore in more advanced stages it is possible to recondition some spare parts and amortize its cost; something unthinkable in early prototypes.
The cost of making a prototype car also depends on how new the model is. Costs are reduced if the vehicle shares a platform with existing cars or if it's a retrofit (technological update of a model) or a restyling.
If, for each iteration carried out by computer, the car had to be tested on a real model, there would not be sufficient financial means to have the wide variety of vehicles that we have currently on the market.
CAD IN AUTOMOTIVE SECTOR
What CAD do automotive manufacturers use?
Keep in mind that sometimes some companies migrate from one Cad to another so the information may vary over time:
There're more useful programs, for example Inventor and Solidworks in car design. The latter is used by many smaller manufacturers. Although it's also used in companies such as Audi and Mercedes. Adams is employed as a CAE in the automotive industry, for MSD and FEM.
In this post we've seen an introduction to the digital phase, we've dedicated it to clarifying the different types of softwares. In the next post we will see a small summary of the different CADs available. It ins't necessary that you download any Cad to follow this online automotive course. Here you can see the index if you have missed any post.