Implementation of a new method for robotic repair operations on composite structures

Abstract

Composite materials nowadays are used in a wide range of applications in aerospace, marine, automotive, surface transport and sports equipment markets. For example, all aircraft have the potential to incur damage and therefore require repairs. These shocks can impact the mechanical behavior of the structure in a different ways: adversely, irretrievable and, in some cases, in a scalable damage. It is therefore essential to intervene quickly on these parts to make the appropriate repairs without immobilizing the aircraft for too long. The scarfing repair operation involves machining or grinding away successive ply layers from the skin to create a tapered or stepped dish scarf profile around the damaged area. After the scarf profile is machined, the composite part is restored by applying multiple ply layers with the correct thickness and orientation to replace the damaged area. Once all the ply layers are replaced, the surface is heated under a vacuum to bond the new material. The final skin is ground smoothed to retrieve the original design of the part. Currently, the scarfing operations are performed manually. These operations involve high costs due to the precision, heath precautions and a lack of repeatability. In these circumstances, the use of automated solutions for the composite repair process could bring accuracy, repeatability and reduce the repair's time. The objective of this study is to provide a methodology for an automated repair process of composite parts, representative of primary aircraft structures.

Optimized Maintenance Decision-Making – A Simulation-supported Prescriptive Analytics Approach based on Probabilistic Cost-Benefit Analysis

“…Replacement of components or systems is often more timeeffective than repair with subsequent quality inspection, in particular when (a chain of) manual processes are involved (International Air Transport Association, 2015). This is why significant research efforts go into approaches for automating respective repair actions to save valuable (down)time and hence costs (Gardiner, 2011;Paquet et al, 2017). This also provides means to decrease the dependence of the repair costs on local conditions, like labor costs of the repair shop region.…”

“…More generally speaking, automated (robotic) repair technologies are gaining momentum, e.g. in the context of composite structures inspection and repairs (Gardiner, 2011;Paquet et al, 2017;.…”

“…Regarding options for refurbishment, progress in repair technology and process automation offer increasingly (cost-) effective options for repairing equipment, instead of replacing it (Wang et al, 2015;Paquet et al, 2017;American Roller Bearing Company, 2020). However, in general, repair is imperfect, such that the post-maintenance life after "repair" is typically reduced as compared with "replacement" (Pham & Wang, 1996).…”