Processing Study of Composite Components Bonded Repairs

Student: Mathieu Préau - PhD Candidate

Supervisor: Prof. Pascal Hubert

Sponsors: Bombardier, L-3 Mas, NRC, CRIAQ, NSERC

While in use, composite materials aerospace structures experience damage, and are in need of repair. Because repairs often take place in a depot directly on the aircraft, bonded scarf repairs are prompted to complex manufacturing challenges. For example, the presence of ingressed moisture, localized heat application, and limited consolidation pressure available, may lead to unacceptable levels of quality and repair performance. This project aims to understand and improve the processing of bonded repairs using out-of-autoclave materials and processes.

Out of this project, a new repair method has been developed to significantly reduce porosity in the bondline, which correlates with higher strength recovery levels.

Presentations and Publications:

P. Hubert, M. Préau, R. Kothari, D. Wilson, and G. Walsh, "Effect of Processing Parameters on Bonded Repair Quality and Strength," presented at the FAA Composite Transport Workshop on Damage Tolerance and Maintenance, Dorval, QC, Canada, 2015.

M. Préau and P. Hubert, "Bonded Repairs of Honeycomb Sandwich Structures: Process Monitoring and Quality Assessment," in the 20th International Conference on Composite Materials Proceedings, Copenhagen, Denmark, 2015.

M. Préau, M. Brodel-Kalou, and P. Hubert, "Void Reduction Strategies for Improved Strength Recovery in Co-Bonded Composite Scarf Repairs," presented at theInternational Conference on Manufacturing of Advanced Composites, Bristol, UK, 2015.

J. Kratz, M. Préau, M. Genest, and P. Hubert , Vacuum-Bag Manufacturing of Honeycomb Structures : Opportunity for in-situ Process Monitoring and Non-Destructive Voidage Estimates", in SAMPE Journal, November/December, 50 (6), 7-16, 2014

M. Préau, K. Bujun, N. Auda, and P. Hubert, "Out-Of-Autoclave Soft-Patch Breathing Solutions for Low Porosity Repairs" in SAMPE Tech, Wichita, Kansas, USA, 2013.

T. Centea, M. Préau, and P. Hubert, "Effect of Layup and Ply Morphology on Void Formation in Out-Of-Autoclave Prepregs" in The 19th International Conference on Composite Materials, Montreal, Quebec, Canada, 2013.

M. Préau, J. Treiber, and I. K. Partridge, "Comportement et endommagement d'un raidisseur omega carbone/époxy renforcé par tufting" in Journées Nationales des Composites 17, Poitiers, France, 2011.

K. Partridge, J. Treiber, and M. Préau, "Deformation and failure in a tufted carbon fabric/epoxy Ω-stiffener," presented at the 11th International Conference on Deformation and Fracture of Composites, Cambridge, UK, 2011.