uni'wissen 02-2015_ENG

approach. One example is electromobility: Electric cars have to be light to achieve a long range – but not at the cost of safety. They need batteries that do not present any danger in the case of an accident. The automobile industry needs other materials for electric cars than for conventional cars, such as rare earth elements like neodymium or lanthanum. “How do we find and extract these materials, how do we process them efficiently, and how do we recycle them?” asks Hiermaier. “We want to make the entire manufacturing process efficient and sustainable, from the raw material to the finished product.” To reach this goal, he is cooperating with industrial partners, especially in the automobile and aeronautical industry. Pushing and Pulling The purpose of the materials tests is to simu- late the complexity of a real accident as faithfully as possible. “We have developed a test rig that allows us to push and pull material in several directions at the same time,” Hiermaier reports. He uses the data from the experiments to create a mathematical description of the material’s be- havior. In this way, he aims to improve simulations on the computer – which for their part serve as the starting point for new tests. “The goal is a program that allows precise predictions,” the researcher explains. This goal has already been achieved in large part. For example, automobile makers simulate full-car crashes for new models on the computer long before they build a proto- type. “The quality of the predictions is high, so the computer models make it clear where prob- lem zones can be expected and how they might be solved. That is also sustainable, because you don’t have to destroy a car to get this data.” All the same, it is still necessary to conduct real crash tests at a later point in development – a crash simulation that achieves the validity of an experiment has yet to be made. The list of materials Hiermaier is studying ranges from steel and aluminum plates and glass for windshields to textiles for airbags. Among them are many so-called composite materials made up of a combination of several materials. One area he is focusing on is carbon fiber com- posite materials for the bodies of cars or air- planes. It is important for him to take a comprehensive approach, says the researcher – and this can make things complex. In a project with an automobile maker, for example, he devel- oped a material made of carbon fibers and res- ins whose mechanical properties seemed promising at first. However, an analysis of the entire production process revealed that the pro- duction would be expensive and the recycling problematic, since separating the materials used to make it again would involve a great amount of energy. In another project, his task was to inte- grate lightning protection into a carbon fiber composite material for airplanes. The current method for achieving this is to include thin metallic threads in the material. The objective of making the material “light and safe” is only partially realized in this case, because the metal threads make the material heavier. There has been little research on alternatives like graphene. Graphene is a two-dimensional form of carbon with good ther- mal and electrical conductivity as well as great strength, but it will be necessary to develop new processing methods and conduct further studies before it is fit for use. Efficient and sustainable – this also means that the materials and parts need to be robust. That is the job of so-called resilience research, which will also be conducted at INATECH. “Resilience means that a system is capable of performing its task as quickly as possible after a “I want to test visions for sustainability from the materials side.” 6

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