Suite of technologies – Structural solutions
Alcoa is broadening its product portfolio by developing metallic and hybrid aerostructures to meet the mission requirements of tomorrow’s aircraft. Through an integrated, strategic and long-term initiative, the company is identifying solutions that offer the best opportunities in maximizing structural performance while also improving aerodynamics.
One optimized structural concept is the use of selective reinforcement, where fiber-metal laminates are bonded between an aircraft’s skin and stringers. Combining such selective reinforcements with Alcoa’s advanced aluminum enable much thinner skins to be used, while still meeting the damage tolerance goals. This concept – already validated in full-scale testing – will allow for extended maintenance inspection intervals and longer useful lifetimes for new aircraft, including the successors to today’s single-aisle jetliners.
Another example is Alcoa’s development of low-aerodynamic drag, self-cleaning skin sheet, taking new approaches in applying the already-proven riblet technology that mimics the bumps on shark skin. Riblets have been demonstrated to maintain airflow attachment over an aircraft’s surface and eliminate large scale vortices. The current technology involves applying riblet film on vinyl sheet with adhesive backing, but drawbacks include a lack of durability in flight conditions, and contamination with dirt and debris that reduces the riblet surfaces’ aerodynamic effectiveness.
Alcoa has developed two new-generation solutions: the rolling of riblets onto structural aluminum sheet and plate; and the use of a thin riblet aluminum sheet that is applied as an appliqué. In both cases, the self-cleaning aspect comes from the use of surface treatment derived from Alcoa’s patented Dura-Bright® product, which allows for easy cleaning with soap and water, and is in widespread use for trucks and other vehicles.