Development of the “High Pressure Repair Dome” system for in-situ high performance repair of aeronautic structures

Abstract

Abstract. As the use of composites for high-performance structures for aerospace applications is constantly increasing, together with the complexity and scale of such structures, an increasingly effort is carried out for the development of advanced techniques for composites structural repair. Mechanical loads and environmental conditions often cause composite damages. If material damage is not extensive, structural repair is the most cost-effective solution. Composite patches can be mechanically fastened, adhesively bonded or co-cured. Bonding or co-curing process provides enhanced stress transfer mechanisms, joint efficiencies and aerodynamic performance. In this paper an innovative and reliable technique to repair damaged composite aeronautical components, named High Pressure Repair Dome (HPRD), is shown. The innovative aspect of this solution is the possibility to bond or co-cure a composite prepreg patch under a pressurized dome, thus using a prepreg compatible with the composite structure. HPRD was developed to allow in-situ repairing on full-scale structures, with the possibility of an accurate control of the parameters of the curing cycle. The advantages and performance of HPRD approach will be discussed and compared with traditional techniques, describing the results achieved and the activity on-course for the full industrialization of this system.

Out-of-autoclave molding of carbon fiber laminates by consolidation with shape memory polymer foams

“…The lamination sequence ended with the forming foam and the shaped dome, both with the same nominal size of 120 × 120 mm 2 . Details on the experimental equipment can be found in previous studies, 14 and the related patent. 18 Figure 6 shows the experimental procedure for CFRP samples.…”

“…Another interesting OOA repairing technique, which can be potentially extended to manufacturing, is the "High Pressure Repair Dome" (HPRD) for in-situ repair of aeronautic structures. 14 In this case, a higher pressure is applied, in comparison with the maximum achievable by vacuum systems, thanks to a flat rubber sheet which is joined with an external reinforced bladder. The bladder is inflated to apply the consolidation pressure and is maintained in contact with the damaged part through vacuum valves.…”