Fiber Composite Technologies

There is currently little experience with the transport of large quantities of liquid hydrogen (LH2) due to the developing market. Tank designs relate to standard onshore storage and transport applications with vacuum-insulated, double-walled austenitic stainless steel structures, which have comparatively high thermal diffusivity and conductivity and increased weight. This currently reduces efficiency due to increased boil-off and unfavourable gravimetric storage density.

New tank concepts are therefore necessary for the maritime production and transport of LH2. Innovative technical approaches from space travel (fibre windings) and for high-temperature applications (thermal barrier coatings "TBC") are being taken up and combined.

On floating multi-purpose platforms in offshore wind farms, composite insulators made of glass-fibre reinforced plastic (GRP) are to be used for the storage of electrical components. The electrically non-conductive core of the composite insulators ensures the safe insulation and reliable storage of converter modules, for example. Due to the offshore use of the platforms, the insulators are subjected to increased cyclical loads as a result of external influences such as wind and wave loads compared to stationary use. Based on this problem, existing insulator concepts are analysed and optimised in terms of materials and design. The overall objective is to reliably verify the fatigue strength of the composite insulators by means of a design concept based on analytical, numerical and experimental verification methods.

Carbon fibre reinforced plastics (CFRP) have been increasingly used in many industries for years. As a result, the amount of CFRP waste materials will increase in the future. Since the production of carbon fibres (CF) is a very energy-intensive process and they are correspondingly expensive, both ecological and economic reasons speak in favour of dismantling the CFRP waste materials and subsequently reusing the CF.

The SolvoCycle research project deals with the use of near- and supercritical fluids for CFRP recycling. This process, known as solvolysis, makes it possible to decompose the plastic matrices of CFRP materials without damaging the fibres. The goals of the project include the recovery of recycled CF and its processing in new CFRP components.

Overcapacities in regenerative power generation can be stored in the form of hydrogen after conversion by means of electrolysis. Gaseous pressure storage places high demands on the pressure vessels, which consist of a thermoplastic inner liner and a wound pressure shell made of carbon fibre-reinforced plastic. On the one hand, the research work pursues the improvement of the composition as well as the processing of the thermoplastic liner material in reactive rotational moulding with regard to its mechanical and physical properties. On the other hand, they are concerned with the computational design and optimisation of the geometry of the individual pressure vessel components to reduce stress, especially in transition areas.

The use of composite materials in shipbuilding is in principle extremely promising due to great design freedom, high corrosion resistance and considerable weight savings. However, strict fire protection regulations prevent the use of conventional fibre-reinforced plastic composites (FRP) with organic matrices, which burn in the event of a fire, releasing heat. The solution to the problem is to substitute the plastics with inorganic, non-combustible matrix systems. However, conventional manufacturing processes for FRP cannot be easily transferred to the inorganic materials. The AnorKomp project focuses on the optimisation and processing of inorganic systems as well as processes for the production of corresponding composite components.