TRUSS: Titanium Reinforced Ultra Strong Structures

The public concern for the environment has increased steadily over recent years and has become a major concern to governments world-wide. The UK has recognised the need to act on greenhouse gas emissions for many years though international treaties as well as national programmes and legislation. COVID-19 has not diminished the desire for a greener and cleaner future, with increased desire to ensure that the investment in recovery from the COVID-19 pandemic should wherever possible focus on cleaner technologies for the future and especially technology where the UK can compete globally or take a world leading position.

Civil aircraft are already being developed to be cleaner and lower emissions through lighter aircraft, more efficient gas turbines, better flight rules and improved aerodynamics. However there is a limit to the efficiency improvements that can be achieved with the conventional tube and wing aircraft design. Therefore engineers re looking at blended wing aircraft which are more aerodynamic and therefore efficient. Blended wing aircraft will require new designs and structures as the tubular fuselage is structurally very efficient.

The most efficient blended wing structures rely on a truss structure made up interconnecting thin tubes with a light weight materials as skin. These tubular structures need to be very mass efficient, easily assembled to make very large structures and capable of long service life as inspection, repair and replacements will be very challenging once the aircraft is in service.

Conventional metals are still relatively heavy compared to light carbon-fibre composites (CFRP), however this can be expensive to produce and can present challenges when joining in large structures due ot the need for adhesively bonded joints and open-assembly curing. The nodes need to be metallic with sufficient interface area for laid transfer between CFRP struts. These can offer relatively poor compression strength versuses tensile, leading to bulkier struts or truss designs to minimise compression loading.

TISICS has developed an innovative solution for very light space system needs. Ceramic fibre reinforced aluminium or titanium exceed the tensile and compression strength and stiffness of aerospace metals and the compression strength of CFRP. When combined with integral diffusion bonded joint nodes, the struts provide greater mass efficient than CFRP. The integral metal nodes can be welded to adjacent struts to enable large wing and fuselage structures in an aircraft assembly environment through robotic welding.

This provides a high integrity, long service life, low mass, truss structure solution for future blended wing aircraft. The UK is the only commercial producer of this technology in Europe.

This project will develop methods to build multi-strut cells and to join struts into larger structures. Demonstrating this will enable faster integration into blended-wing development projects.