Extra aircraft protection for new engine design
The EU is funding numerous projects that support the unique public-private partnership Clean Sky between the European Commission and industry to radically decrease the environmental impact of air transport. Among the concepts to enhance engine efficiency is an open rotor design in which the rotating engine components are not contained in conventional engine housing. The design makes it imperative to include new low-weight shields to protect the fuselage and other critical structures from high-velocity shrapnel following an engine burst. Such shields were developed within the context of the EU-funded project IMPSHIELDA (Impact shield A). Scientists successfully developed three shields according to three projectile size and weight classes, all incorporating high-performance fibres to meet the requirements for strength and weight. In addition, they developed associated low-cost manufacturing methods, bringing the technology to a relatively high maturity level. During a high-speed impact event on a composite laminate, each layer's reaction can vary significantly depending on its location within the laminate. Scientists used a gas gun to study the impact phenomena on shielding materials. Fibres were combined with thermoplastic or thermoset matrix materials. In the first shield, the team sprayed a thermoset powder coating into a closed mould so as to control the resin amount between the layers. For better impact resistance, fibres were hybridised with ultra-high molecular weight polyethylene fibres in the second shield. And in the last one, scientists used cross-ply laminates comprising foam layers. Laminates contained insufficient resin for complete bonding of the reinforcement. Innovative composite ballistic shields are necessary to protect aircraft from damage by failure of engine components. With the manufacturing methods tested and validated, the project's work ensures rapid development and commercialisation of improved ballistic shields to support the flight readiness of Clean Sky's best designs.
