We talked to Prof. Rudolf Voit-Nitschmann, who explained the significance of lightweight construction, primarily in aircraft engineering but also in other industries. He also tells us about some of the developments he thinks the German lightweight construction field can expect further down the road.
Professor Voit-Nitschmann, lightweight construction has always been a key success factor in aircraft engineering. How is that relevant for establishing lightweight construction in other industries?
Looking back through history, we can see that aluminum lightweight construction was first introduced in Germany with the construction of Zeppelin airships. Back then Claude Dornier made major contributions to this area as an employee at the Zeppelin plant, and later when he founded the Dornier plant. Still today, the aerospace industry is the driving force behind lightweight construction – even in other industries. Lightweight construction is mainly becoming more important now because of electric vehicles. Take, for example, the BMW i3. Its passenger cell is composed entirely of fiber-reinforced plastics (FRP).
In the beginning, lightweight construction could be boiled down to one simple principle: replace heavy materials with lightweight ones. Simply speaking, this meant replacing steel with aluminum. This definition won’t work anymore – there’s far greater demand for intelligent solutions, combining materials with functionality, to ensure the components are not just lighter, but also safer, easier to work with, and more resource efficient. What does this mean for the future?
It’s true that lightweight construction goes back to simply selecting lightweight materials. To do this, identical components were simply replaced with those made of lighter materials. With the rise of what we now call functional lightweight construction, combined with integrated lightweight construction, we can now meet other functional requirements in addition to simply reducing weight. FRPs can be designed based on the intended use, knowing the stresses that the fibers will ultimately be subjected to. With the right mold forms it’s easy for us to meet aesthetic or aerodynamic requirements and get the geometry right. In car passenger cell construction, we can reduce the number of components compared to sheet metal construction. In integrated lightweight construction, functional features such as insulation and sensors can also be integrated.
The use of hybrid materials is opening up new avenues for industrial processes. What potential do you think exists in terms of future developments, especially in Germany which is a stronghold for industrial manufacturing?
Developing hybrid lightweight materials is a big part of the modern automotive industry. The whole idea is based on selecting just the right materials for each component, taking various aspects into account relating to lightweight construction, manufacturing, and costs. But hybrid materials are also used in aircraft engineering, like the use of glass laminate aluminum reinforced epoxy (GLARE) in the A380. This is a glassreinforced aluminum. One of this material’s main benefits is that it reduces the risk of cracks spreading from damaged areas. We haven’t begun to fully tap into the potential of hybrid materials and construction methods. Here in Germany, we are among the leaders in the field of materials research.
Part of what you do is look at the use of lightweight construction technologies in aviation. What kinds of things does this industry hope to achieve with lightweight construction? Or to be more specific and provocative: Does anything ever change in the aerospace industry?
The most important requirement is still weight reduction. Construction regulations also stipulate further important requirements for an aircraft to be registered, so properties like damage tolerance or good fatigue behavior are also important. Electric aircraft are becoming more and more popular – at least in general aviation. The e-Genius touring motor glider is an example of this. It was developed as an experimental aircraft at the Institute for Aircraft Engineering at the University of Stuttgart. Carbon fiber composite constructions are essential for the next generation of electric aircraft.
If you wouldn’t mind making a prediction for the future, what do you see for the future of lightweight construction in Germany, particularly in Baden-Württemberg?
The impending energy transition, the demand for energy savings, and environmental friendliness will come together to drive electric vehicles forward in all sectors – cars, two-wheeled vehicles, aircraft. Lightweight construction and fiber composites will become more prevalent, even in the fields of medical technology and robotics engineering. The focus will be on improving processes in order to make series production more economical. What’s more, the automated textile manufacturing processes for fiber composites will become more important for producing highstress components. There is a competence center that focuses on these aspects in its research, at the Institute of Aircraft Engineering, which is based at the University of Stuttgart. And finally, I’d like to mention the glider manufacturers Schempp-Hirth Flugzeugbau and DG-Flugzeugbau. They’re industry forerunners in Baden-Wurttemberg. These two companies are global leaders in their field. There are also a great number of Steinbeis Enterprises working in the field of lightweight construction. At our Steinbeis Flugzeug- und Leichtbau GmbH, we create lightweight structures for aircraft made exclusively of fiber-reinforced composites. In addition to lightweight construction, our core competence lies primarily in the area of materials certification in accordance with the respective aerospace regulations.
Prof. Rudolf Voit-Nitschmann is director of the Steinbeis Transfer Center for Aerodynamics, Aircraft Engineering, and Lightweight Construction, as well as managing director of Steinbeis Flugzeug- und Leichtbau GmbH. His Steinbeis Enterprises provide customers with access to extensive know-how and expertise in the field of aircraft development and lightweight components in fiber-reinforced plastic construction. In 2011, Rudolf Voit-Nitschmann was awarded the Steinbeis Foundation’s Transfer prize – the Löhn award – as a special award for outstanding contributions to technology transfer.