N231-069 TITLE: High-Rate, Reduced Life Cycle Cost Airframe

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Autonomy;General Warfighting Requirements (GWR)

OBJECTIVE: Develop technologies in the areas of 1) structural concepts, 2) design and analysis methods, 3) materials and processes (M&P), and 4) manufacturing that enable lightweight airframes with reduced total life cycles cost while being compatible with high-rate production.

DESCRIPTION: To enable successful manned-unmanned teaming (MUM-T)-based Concept of Operations (CONOPS), a sufficient number of Unmanned Aerial Vehicles (UAVs) must operate with manned assets. This requires that the total life cycle cost of UAVs must be much lower than that of the manned assets such that enough quantities can be acquired and operated. Here, the total life cycle cost is defined as the non-recurring development cost (engineering, tooling, capital equipment, etc.), recurring production cost, and sustainment cost. As important, those quantities of UAVs must be acquired in a relevant time period�i.e., a higher production rate than current state of the art must be achieved. Moreover, both goals�reduced life cycle cost and high production rate�must be achieved without excessive loss in structural efficiency (i.e., weight) and aerodynamic efficiency (i.e., geometric/assembly tolerances).

In order to address these three constraints�i.e., reduced life cycle cost, high production rate, and maintenance of relevant efficiencies�this SBIR topic seeks solutions in the following areas. The proposal should address both approaches but may emphasize one over the other:

DESIGN AND ANALYSIS METHODS:

The cost and time of engineering development of a new airframe is dependent on the chosen structural concepts and the methods and tools to design and optimally size them. However, in meeting the cost and schedule goals, the structural efficiency must be maintained to some level. Hence, cost, schedule, and performance goals can be met with automation in design, analysis, and optimization methods. Examples include:

� Tools and methods to reduce the nonrecurring cost of development of air vehicle external and internal loads models

� Tools and methods to reduce the nonrecurring cost of structural sizing and analysis for chosen structural concepts for multiple failure modes, including the ability to define user-based failure criteria and associated allowables

� Reliability-based structural sizing methods and implementation of the methods in above tools for sizing. Goal is to be able to size the airframe to meet a Single Flight Probability of Failure (SFPoF) requirement

� Tools and methods for 1) automated conversion of analytical laminate distribution in finite element model (FEM) from above to CAD/manufacturable laminate design distribution, and inversely 2) automated mapping/conversion of CAD laminate design distribution to FEM

 

M&P AND MANTECH:

High-rate production of low cost airframe will require novel M&P solutions and manufacturing methods. The focus of these methods should be on reducing the recurring cost of production with consideration for economic viability of investment in non-recurring cost items. Desire is to reduce touch labor and not the labor rate. Note that the M&P and ManTech solutions must be integrated and proposed together. Examples include:

� Malleable composites (e.g., thermoplastics, vitrimer), associated parts fabrication methods and joining/assembly methods. Advancement of malleable composite M&P and manufacturing methods must be in the context of compatible structural concepts (acreage and joints) for maximum structural efficiency and include the assessment of degraded material properties on structural weight at component- or vehicle-level. Field-repair methods should be considered.

� High tolerance, responsive, high-rate composite structures assembly methods. Two tolerances must be addressed: 1) tolerance within build of an assembly (such as wing or fuselage sections) and 2) tolerance between assembly-to-assembly mating (such as outboard wing to center wing, wing-to-fuselage, etc.).

 

KEY AIRFRAME PARAMETERS:

� Structural assembly size of at least 15 ft x 6 ft x 6 ft with final component/assembly size that is at least 40 ft x 6 ft x 6 ft. This is to provide context for the size of assemblies that parts fabrication and manufacturing methods must address.

� 50% reduction in non-recurring engineering design development and recurring production cost for air vehicle structures

� Production rate of 20 shipsets per month with surge capability.

 

PHASE I: Develop concepts for technical solutions in design/analysis engineering and M&P/manufacturing solutions and demonstrate key aspects of those solutions. For example, for design/analysis methods solution, develop a workflow/architecture and demonstrate key parts of or the entire workflow/architecture on a representative structural component. For new integrated M&P/ManTech solution, subscale structural component (e.g., flat stiffened skin, single cell closed box with joining concepts) should be designed and manufactured and preferably tested. For new materials solution, coupon-level and/or element-level tests should be performed to assess basic mechanical properties such as unnotched and notched compression strengths, interlaminar shear and tension strengths, preferably to include moisture/temperature effect. For all proposed solutions, cost benefits should be estimated.

PHASE II: Mature solutions using one or two representative but subscale component(s)�e.g., wing, empennage, or fuselage. Multiple replicates should be designed, built, and tested., Measure/demonstrate time to completion of engineering design and analysis, time to build detailed parts, time to assemble parts to component, tolerances achieved, quality achieved, learning curve achieved, and structural strength achieved. If responsive/flexible assembly approach is being developed, ability to reconfigure the approach for different assemblies must be shown, either physically or virtually, with estimation of time to complete reconfiguration. In the maturations of the solutions, additional constraints such as subsystems/systems integration should be considered. Prepare a final report and Phase III plan.

PHASE III DUAL USE APPLICATIONS: Demonstrate integrated design, M&P, and manufacturing solutions at full scale component level with additional constraints such as subsystems/systems integration. Show reduction in cost/schedule with relevant structural efficiency and aerodynamic cleanliness in a repeatable manner. Potential use of the lessons learned in commercial UAV market should also be explored.

REFERENCES:

1.       Tuegel, Eric J. 2020. "Aircraft Structural reliability and Risk Analysis Handbook Vol 2", WPAFB, AFRL-RQ-WP-TR-202-0069. https://apps.dtic.mil/sti/pdfs/AD1111926.pdf

2.       Hamilton, Thomas and Ochmanek, David A. 2020. "Operating Low-Cost, Reusable Unmanned Aerial Vehicles in Contested Environments: Preliminary Evaluation of Operational Concepts. Santa Monica, Calif.: RAND Corporation.

3.       Marx, William J.;, Mavris, Dimitri N. and Schrage, Daniel P. 1998. "Cost/Time Analysis for Theoretical Aircraft Production." Journal of Aircraft 35 (4): 637�46. https://doi.org/10.2514/2.2348

4.       Barrera, Nicholas, ed. 2021. "Unmanned Aerial Vehicles." Robotics Research and Technology Series. New York: Nova Science Publishers

5.       Mason, Hannah, "Reprocessable thermosets and thermoplastic epoxies: An expanding landscape", 2020, CompositesWorld; https://www.compositesworld.com/articles/reprocessable-thermosets-and-thermoplastic-epoxies-an-expanding-landscape

6.       Elhjjar, Rani, ed. 2017. "Additive Manufacturing of Aerospace Composite Structures : Fabrication and Reliability." Warrendale, PA: SAE International

7.       Sloan, Jeff, 2019, "Large, high-volume, infused composite structures on the aerospace horizon" 2019. CompositesWorld; https://www.compositesworld.com/articles/large-high-volume-infused-composite-structures-on-the-aerospace-horizon

 

KEYWORDS: Life Cycle Cost, High-Rate Manufacturing, Unmanned Air Vehicles

---