In-line Quality Assurance for the Manufacturing of Carbon Fiber Reinforced Aircraft Structures

Carbon fiber reinforced polymers are playing a key role for future aircraft structure design concepts as the newest technical developments for aircraft models B787 and A350 are showing. Due to the specific mechanical properties of this composite material and the novel manufacturing and machining techniques for large-scale CFRP made aircraft structures, it is necessary to establish an adequate process integrated quality assurance system that enables a cost-effective automated manufacturing route. Beside upcoming releases of numerous new reference guidelines based on well defined technical tolerances, it is necessary to look for non-destructive test techniques that are capable to monitor the different manufacturing steps and to detect defects and tolerance deviations within the processing route. For choosing reliable NDE techniques some key criteria as for example non-contact measurement, imaging options, penetration depth, scanning speed, the maximum possible coverage area and others have to be considered. The decisive step for applying new NDE methods is the scale up from laboratory conditions to large component testing in an automated manufacturing environment. Beside the ability to find and evaluate small microstructural features within a large CFRP structure component, it is also necessary to establish an intelligent software infrastructure which allows to exchange, compare and merge data sets of different non-destructive scanning techniques in terms of a reliable signal interpretation