The AMRC was involved in a work package on the programme, which was collaboration between Airbus (lead), Messier-Bugatti-Dowty, TWI, AMRC with Boeing (ASTC and Composite centres) and TISICS. A significant proportion of the funding came from the Technology Strategy Board. The project was commissioned in response to the pressing need of reducing the weight of the overall aircraft without compromising on strength, fatigue and durability, whilst improving service life and increasing the time between major services. Research & development was integral to achieving this, in addition to addressing the overarching theme of reducing the cost of materials and production. Therefore, the project team focused on identifying new materials and manufacturing processes to produce lighter weight actuators and braces for aircraft landing gear. Current actuators are largely constructed from 300M. It is a high tensile strength steel that has been used for the production of landing gear for many years, and is in many ways an ideal solution to the engineering and material properties challenges.
However, it has one drawback - it is a steel and therefore susceptible to corrosion. Consequently, the challenge was in providing a solution that met the performance of 300M whilst exhibiting adequate corrosion resistance.
Research & Development
The team investigated the feasibility of using an advanced carbon composite actuator rod overclad with steel, laser deposited stainless steel, titanium silicon carbide metal matrix composites, in addition to testing associated with high tensile steel e.g. Ferrium S53®.Full scale components of each were created in order to investigate their design, ease of manufacture, weight and their performance, all of which were tested against the existing component as a benchmark. Focusing on the actuators created from steel clad advanced composites, one important criterion was to analyse the interface between the metallic ends and composite body. It was fabricated by braiding the carbon fibre over a core and the metallic ends. This was then placed in a mould, into which resin was injected under high temperature and pressure - a process called resin transfer moulding. The core was made of a water soluble ceramic, which was removed after injection of the resin leaving a hollow component.
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