Two-stage leak detection in vacuum bags for the production of fibre-reinforced composite components

Abstract

The increasing application of fibre-reinforced composite components in aviation results in new problems in production when compared to the conventional production of components from aluminium alloys. For instance, the existence of leakages in the vacuum bag can substantially impact the component quality. A significant increase of both time and cost, and even the rejection of the entire component are caused. Commercially available methods are suitable for identifying leakages in vacuum bags; however, their application is predominantly associated with high outlay in labour and time, and, thus, high costs. Market analysis and comparison of different available leakage detection technologies conducted in the course of the advanced detection of leakages project with our collaborative partner Airbus Operations GmbH Stade has shown that the combination of run-time based leakage detection and infrared thermography is the most promising concept for quick, reliable, and automated identification of leakages in vacuum bags for large components. In combination, both technologies are able to compensate for their respective detection limits, and significantly reduce the time required. In addition to the analysis and assessment of different technologies for leakage detection, the investigations presented also include the development of run-time based leakage detection using sensors integrated into the vacuum bag. Furthermore, the linking, further development, and automation of leakage detection using infrared thermography are described.