Benefits of Virtual Prototyping.

Earlier this year, Expliseat announced that ESI Group’s Virtual Seat Solution help them to certify their titanium-composite aircraft seat. The tool allowed Expliseat to bring their testing into the virtual realm allowing for more iterations and innovations. In the end, Expliseat reduced the weight of the seat significantly. But how did the Virtual Seat Solution help to design a 4 kg (8.8 lbs) seat sturdy enough for European Aviation Safety Agency (EASA) certification?

“By using Virtual Seat Solution engineers can fine tune the fabrication, assembly, safety, and comfort of the seat virtually. This testing can continue until you are sure it will pass all certifications once manufactured physically. After this ‘pre-certification’ you will still need to perform a final physical certification. But the program allows you to anticipate issues and solve them during the design phase before production,” answered Caroline Borot Marketing & Business Development Manager at ESI Group.

She added, “The idea is to have a virtual prototype to assess product issues. In the standard process of design, you create a prototype, test it and then submit innovations if there is time late in the development cycle. With a virtual prototype, however, you can perform all the tests simultaneously and anticipate issues early in the development cycle. This allows for more innovation and more fixes early in design saving time and money. With the old method of design, it’s too late to change deeply the seat design .”

What can you Test with the Virtual Seat Solution?

The Virtual Seat Solution brings a number of different assessments to your fingertips. Some of these assessments include: thermal comfort, pressure/ergonomic comfort, vibration, frame manufacturing, assembly, and crash/safety.

As all of these simulations run at once, you have time to test for things you will typically not be able to assess with the time constraints of physical prototypes. These added assessments allows you to make trade-offs where you would normally not have enough information to make an informed decision. This information will allow engineers to design more comfortable and functional seats.

Borot said, “The tool is very easy allowing designers to be very creative. You are free to imagine what you want done and do it. You will have the time to test many things you customarily don’t have time to look into when taking the classic design approach. You typically focus first on crash & safety tests and cannot easily perform the right tradeoffs with the other performances with this slow approach. With the virtual prototype it is easy and quick to test.”

How does the Virtual Seat Solution Compare to FEA?

Traditional FEA technology is used behind the scenes of the Virtual Seat Solution for many simulations. The application and models, however, are dedicated to seat design, integration, and best practices. Users are guided through dedicated functionalities and design tools. As such this tool’s interface will not look like a traditional FEA software; it will look more like a seat design interface.

Borot explained, “Unlike traditional FEA analysis, your model will be multipurpose. Using one model you can assess performances like vibration, crash, comfort, and more. These are fully predictive prototypes. Even more convenient is the fact that you can chain the simulations together. Stress and strains during the fabrication simulation can have an effect on the metal frame tested in the crash test. Or the pressure on the seat during sewing can generate a local strain on the cushion affecting the seat’s comfort. You can start from manufacturing to performance of the prototype seamlessly.”

Users start with a CAD model and add mechanical properties to each component. The more details the user includes the closer the virtual model will be to a real prototype. The results are limited by the user inputs. Users can make small tweak to the design without going back to CAD. For instance, you can morph a sew line on the seat using the internal tools. However, for big changes it is recommended to go back to CAD.

Sewing simulations.

The tool then meshes the CAD for simulations. You will perform the same safety tests as you would in reality with identical load cases, accelerations, and analysis. But with the Virtual Seat Solution you are able to see internally how each component of the seat reacts. This is something you cannot do in reality.

“We are continuously working to extend the scope of the solution, collaborating with customers who request new performance tests or new assessments,” said Borot. “We have recently extended the scope to include thermal comfort this past year. As more requests come in, we will make more improvements as needed.” Who should use the Virtual Seat Solution?

Who should use the Virtual Seat Solution? 

The Virtual Seat Solution was originally created for the automotive industry. The tool’s applications, however, have expanded to include aeronautics, construction vehicles, trucks, and more. Even some furniture manufactures have been known to use the software - though this is not a wide practice.

As for the aviation seat producer Expliseat, they were happy with their results. The seat is twice as light as comparable light weight seats in the market. This adds up to a fuel savings of $300,000 to $500,000/aircraft-year. Now their titanium-composite seat will be featured on the Boeing 737 and Airbus 320.

Vincent Tejedor, CTO of Expliseat, said “Virtual Prototyping is a proven industrial approach to pre-certify the manufacturing process and performance of an innovative product, such as our Titanium seat. Our experience working with ESI’s Virtual Seat Solution confirms the efficiency of this solution in speeding up innovation. Virtual Seat Solution has helped us reduce drastically the development time usually required to design an innovative product, and has allowed us to increase the business value of our company in record time!”