OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Trusted AI and Autonomy;Advanced Computing and Software The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. OBJECTIVE: This topic seeks to develop a new design and manufacturing paradigm capable of rapidly producing a low-cost, lightweight, full-scale airframe structure for a next-generation aircraft system by combining topology optimization (TO) and additive manufacturing (AM) technologies. The new design tool and printed structure will be evaluated by ground testing, during which the new and baseline structures will be compared based on weight, stiffness, strength, cost, fatigue life, and manufacturing time. DESCRIPTION: The Department of the Air Force is exploring the concept of design for manufacturing to enable agile development and delivery of full-scale airframe structures for next-generation air vehicles. Air Force Research Laboratory (AFRL) is assessing emerging airframe design tools and 3D printing technologies to address rapidly changing warfighter needs more efficiently during airframe design and manufacture. The emergence of new design and manufacturing technologies, such as TO and AM, provides possible solutions to improve the development and delivery of capable airframe structures. First, TO offers design freedom, allowing structures to be designed around load paths rather than constrained to orthogonal rib and spar layouts. Second, AM offers manufacturing freedom, using truly toolless fabrication to manufacture complex geometries without the need for extensive machining. The combination of TO and AM opens the door to new possibilities in the design and manufacture of airframe structures. Current developments in TO and AM technologies have shown the power of TO and AM in addressing design and manufacture at the component scale, but further work is needed to prove the power of TO and AM at the structural scale. For example, TO is widely used to design optimal geometries at the component scale, but the design of a large-scale structure system with TO has yet to be proven. Similarly, AM technologies are available to manufacture parts at the component scale, but the inherent link between the printing footprint of AM machines and maximum producible part size precludes the complete manufacture of full-scale structures. This effort aims to explore a new hybrid way of designing and manufacturing a full-scale, load-bearing airframe structure at a fraction of the time and cost without sacrificing structural capabilities such as weight, stiffness, strength, and fatigue life. The hybrid approach will harness the complementary capabilities of TO and AM in creating an approach that can adapt to fast-changing mission needs. TO will be used to design an airframe structure that is divided into the minimum number of segments, considering the maximum AM print part size. Toolless fabrication capability, enabled by AM, is essential to produce the resulting TO structures efficiently. The entire system should be printed, including the wing skin, and each segment will be printed with novel joint concepts to minimize assembly efforts and the number of parts. The material is not limited to polymer, chopped/continuous fiber, metal, or any combination thereof to build the most weight-efficient structure, but the load-bearing airframe structure should satisfy the stiffness and strength requirements of over a 10,000 lb vehicle. A baseline structure will be provided upon selection of the award. The main deliverable for this topic is a redesigned, full-size, printed airframe structure matching AF's provided baseline structure. The contractor should analyze, design, build, and test to validate the new printed structure and demonstrate that the fabricated structure will be equivalent to or outperform the baseline structure. PHASE I: As this is a Direct-to-Phase-II (D2P2) topic, no Phase I awards will be made as a result of this topic. To qualify for this D2P2 topic, the Government expects the applicant to demonstrate feasibility by means of a prior Phase I-type effort that does not constitute work undertaken as part of a prior SBIR/STTR funding agreement. The proposer should have already demonstrated a technology to prove the concept at a scaled or component level, including a feasibility study prior to submitting a proposal. This includes determining, insofar as possible, the scientific and technical merit and feasibility of ideas appearing to have commercial potential. It must have validated the product-market fit between the proposed solution and a potential AF stakeholder. The applicant should have defined a clear, immediately actionable plan with the proposed solution. Relevant areas of demonstrated experience and success include designing and modeling prototype concepts, concept development, concept demonstration, concept evaluation, and field testing. Phase I-type efforts include the assessment of the structural concept and the potential for 3D printing. PHASE II: This effort shall conduct analysis, tool development, experimentation, and fabrication of representative full-size prototype systems to address unique requirements that may not be otherwise met by a scaled conventional airframe design and fabrication. PHASE III DUAL USE APPLICATIONS: Phase III shall include the fabrication of more complex prototypes, such as a full vehicle. REFERENCES: 1. Taylor, Robert & Niakin, Bijan & Lira, Nicholas & Sabine, Gavin & Lee, Joakim & Conklin, Craig & Advirkar, Sangram. (2020). Design Optimization, Fabrication, and Testing of a 3D Printed Aircraft Structure Using Fused Deposition Modeling. 10.2514/6.2020-1924. ; 2. https://www.ga.com/ga-asi-partners-with-divergent-technologies-inc; 3. https://www.forbes.com/sites/erictegler/2023/04/27/uas-startup-firestorms-ambition-to-crank-out-combat-drones-fast-cheap-and-en-masse-is-a-lesson-for-dod/?sh=168b9f871409; 4. https://aviationweek.com/aerospace/advanced-air-mobility/firestorm-flies-modular-3d-printed-small-uas; KEYWORDS: topology optimization; additive manufacturing; low-cost UAV; design for manufacturing; ACP; lightweight structure;
