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NASA wing survives 127% of its design load
NASA’s SWEET-15 wing survived expected flight loads and failed only at roughly 127% of its design limit, advancing truss-braced aircraft research.
Image: TechXplore
NASA has pushed a 15-foot (4.6-meter) wing model beyond its intended structural limits—and the results strengthened the case for a radically lighter aircraft design.
The Structural Wing Experiment Evaluating Truss-bracing, or SWEET-15, is designed to test a long, thin wing supported by an aerodynamic strut. The configuration builds on NASA’s earlier Transonic Truss-Braced Wing concept, which aims to reduce fuel consumption in future commercial airliners.
NASA researchers needed to establish how the lightweight structure would respond to the forces encountered during flight. SWEET-15 combines five advanced composite manufacturing and assembly technologies developed to enable its unusual structural design. NASA’s Langley Research Center in Hampton, Virginia, designed and fabricated the test article before it was transported to NASA’s Armstrong Flight Research Center in Edwards, California.
How NASA tested the truss-braced wing
Over several months, engineers deliberately bent the model in Armstrong’s Flight Loads Laboratory. Strain and load sensors—including fiber-optic strain sensors—were distributed throughout the structure to measure its response as the forces increased.
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The sensor data matched NASA’s computer-model predictions. The wing handled the anticipated in-flight forces without issue, giving researchers confidence in the manufacturing and connection methods used for SWEET-15.
NASA Langley developed the manufacturing process with the Integrated Structural Assembly of Advanced Composites robot, which produces lighter and stronger composite aerospace structures.
The final phase was a deliberate test-to-failure. Engineers increased the load beyond the wing’s design limit to determine where and how the structure would break. Failure occurred at roughly 127% of the design limit load, with visible damage near the wing’s back edge and in its upper cover.
That failure exposed how the joints linking the wing to its main strut and a secondary jury strut behave beyond the expected flight envelope—information that will help refine future designs.
First representative composite evaluation
NASA says this was the first structural evaluation of a representative composite truss-braced wing configuration. The effort brought together teams from multiple NASA centers and projects, including the agency’s Fiber Optic Sensing System, which was developed to collect data from aircraft and spacecraft.
Langley engineers handled the wing’s design, analysis, manufacturing, safety preparations and laboratory setup. Researchers will now analyze the test data to guide future airframe designs and NASA’s work on more efficient aviation technologies.
The project is being conducted through NASA’s Subsonic Flight Demonstrator project within the agency’s Research Technology Mission Directorate. The test’s final result—structural failure only after loads reached roughly 127% of the design limit—marks a milestone for the truss-braced aircraft concept.
Frontier Editor
Dan is our resident futurist, covering electric mobility, space exploration, and the smart home. He's interested in atoms just as much as bits. Whether it's a new battery chemistry, a reusable rocket, or a protocol that finally makes IoT devices talk to each other, Dan breaks down the engineering that pushes humanity forward.
via TechXplore
