Italian manufacturing company CRP Technology has revealed yet another interesting case study for its composite Windform 3D printing materials, this time in collaboration with the Department of Aerospace Science and Technology at the Politecnico di Milano (PoliMi). CRP Technology provided its 3D printing expertise and composite materials to support PoliMi’s “Aeroelastic Flutter Suppression (AFS)” and “GLAMOUR” projects.
The AFS project, a joint effort between PoliMi and the University of Washington, set out to test different active control system technologies with the aim of attaining Active Flutter Suppression. The GLAMOUR project, for its part, focuses on the technological optimization and experimental validation of Gust Load Alleviation (GLA) control systems for advanced Green Regional Aircraft produced by Leonardo Aircraft Division. For both projects, CRP aided in the additive manufacturing of parts for the aeroelastic wind tunnel demonstrators.
More specifically, the company helped to manufacture a series of external aerodynamic segments for the projects’ respective wind tunnel demonstrators. CRP leveraged professional selective laser sintering (SLS) 3D printing and its Carbon-composite Windform XT 2.0 material for the tasks. The material was also used to produce a horizontal tail for the AFS wind tunnel demonstrator.
Traditionally, the aerodynamic sections for the wind tunnel demonstrators would have been produced using carbon or glass fiber fabrics dry laminated onto styrofoam blocks cut to match the aircraft’s wing shape. This method did not produce the best results in terms of surface quality and was too time consuming. As showcased through CRP’s efforts, 3D printing proved to be a suitable alternative.
In the design and development of aircraft components, aerodynamic features are crucial, as they help to reduce drag on the aircraft and enable faster speeds and efficiency. When designing a wing, for instance, aerodynamic features enhance performance and transmit aerodynamic loads to the internal structure.
Other factors also come into play when developing an aircraft wing, including weight and strength. At PoliMi, the team set out to create wing components that were lightweight, stiff and externally smooth.
Notably, for the wind tunnel testing phase, the aerodynamic components are not typically subjected to high stress, since they are not the primary structure of the aircraft, but they must fulfil their job of transmitting the aerodynamic forces to the flexible spar, efficiently acting as an interface between the incoming air and the internal structure of the wing. This meant that even for the wind tunnel model, the wing components had to have a high quality surface finish.
CRP Technology worked with PoliMi to optimize the wing components, leveraging SLS 3D printing technology and its composite materials to produce parts that were both smooth and lightweight. Before that, the CRP and PoliMi teams started with an in depth analysis of 2D and 3D files of the aircraft model. At this stage, CRP made recommendations to optimize the geometries of certain parts to help reach the strict weight and stiffness requirements.
When the 3D models were ready, CRP 3D printed the parts using its Windform XT 2.0 material, whose mechanical properties met the needs of the project in terms of stiffness, weight and surface quality.
In the end, the 3D printed wing components, including connectors for the main spar, hinges and electric drivers, for the AFS project were an overwhelming success. The GLAMOUR project also saw success thanks to CRP technology’s Windform composite material, which enabled the PoliMi team to attain the combination of vibration frequency targets and the forced mass constraints.