Abschlussbericht Projekt TOP-Design

Kurzfassung

For the next generation of airliner-fuselages, it was decided to use composite materi-al instead of aluminium. The door-surround-structures (dss) have shown to be one of the most complex parts to be adapted. On the one hand, the manufacturing accuracy of composites differ highly to metal parts, on the other hand the thickness of the reinforced skin must be increased to coup with the high cut-out loads which generates new problems like secondary bonding effects. The third problem is the impact sensitivity of composites. The project target is to find solutions for the composite adapted door surround struc-ture to reduce the total costs. A systematic approach has been chosen to find and evaluate the requirements, find innovative new concepts, to benchmark them and to discuss the new ideas with experts. The composite process chain has been analysed in detail to find weak points. A weak point is the draping simulation, which generates in dependence of the user experience flat patterns with poor accuracy. A detailed benchmark has been performed to find the optimal parameter, algorithm and soft-ware. The chosen dss concepts have been built as FE and CAD-models and the structural performances has been benchmarked. It has been shown that one of the best con-cepts is the hybrid-laminate, where titanium layers are used to coupe with high shear stress especially in the cut-out corners. To overcome the impact detection problem, the SHM method has been expanded for hybrid materials. Here, basic research was necessary to get the right parameters to simulate the material behaviour and to find the ideal positions for actors and sensors. QS and NDT methods have been tested for highly complex integral structures. The most promising dss concepts have been manufactured as rapid prototyping models. Manufacturing trials for hybrid reinforced laminates and well as some drap-ing tests have been performed and evaluated. All results are now available and can be used for the improvement of composite door surroundings as well as for other complex highly loaded structures.