The vital step towards super light carbon fiber cars and airplanes
In recent years, carbon fiber reinforced plastics (CFRP) have become increasingly established and used in automobile and aircraft manufacturing as well as in everyday items (e.g. sports equipment). Nevertheless, there are still unanswered questions. Therefore, it is useful to briefly explain what fiber reinforced composite is: The material is made of many thin fibers (carbon fibers) which are held together with a kind of “adhesive”. In relation to their weight, the fibers have extremely high strength and rigidity in the direction of the fiber. For loads traversing across the fiber direction, however, the forces are only transferred through the “adhesive”, which is very low in strength. In an actual component, the fibers must therefore be distributed in terms of quantity and direction in a way which ensures that the necessary fibers are available in every direction of load. In this way, a component can be precisely tailored based on its weight and can therefore be built very lightweight.
However, a specific challenge appears in areas where the component is connected with the surrounding structure (e.g. by screws). In those areas where the load is introduced, the material is loaded in a very concentrated and complex way. Today, these areas require elaborate constructions and designs, which generally makes production very expensive. The challenge is to now develop simple load introduction areas that are inexpensive to produce and are functionally on par with the elaborate design variant.
Figure: Specimen geometry for pre-investigations
In order to design more effective load introduction areas, the mechanisms that act at the load introduction area first have to be understood. For this purpose, tests and calculations are performed. The calculations provide insights that cannot be measured in the tests, while the tests provide input values for the calculations, identify weaknesses and ultimately validate the calculations. Based on these results, new design and engineering solutions will be developed for optimized load introduction areas. This work is accompanied by research and development of suitable manufacturing processes, with the aim of producing low-cost components as well.
The goal of the project is to develop cost-efficient, weight-effective and mass production-capable solutions for typical load introduction areas of carbon fiber components for the aerospace and automobile industry. This is the only approach that allows the “carbon fiber” material to fully prove its advantage of enabling extreme lightweight construction. Ultimately, all of these efforts bring to light one of the most important challenges: achieving sustainability through energy savings.