Wright-Patterson Air Force Base

About: Wright-Patterson Air Force Base is a other organization based out in Wright-Patterson AFB, Ohio, United States. It is known for research contribution in the topics: Laser & Mach number. The organization has 5817 authors who have published 9157 publications receiving 292559 citations. The organization is also known as: Wright-Patterson AFB & FFO.

Flapping Wing Structural Deformation and Thrust Correlation Study with Flexible Membrane Wings

Abstract: This experimental study investigates the relationship between flapping wing structure and the production of aerodynamic forces for micro air vehicle hovering flight by measuring full-field structural deformation and thrust generation. Results from four flexible micromembrane wings with different skeletal reinforcement demonstrate that wing compliance is crucial in thrust production: only certain modes of passive aeroelastic deformation allow the wing to effectively produce thrust. The experimental setup consists of a flapping mechanism with a single-degree-of- freedom rotary actuation up to 45 Hz at 70 deg stoke amplitude and with power measurement, a force and torque sensor that measures the lift and thrust, and a digital image correlation system that consists of four cameras capable of capturing the complete stroke kinematics and structural deformation. Several technical challenges related to the experimental testing of microflapping wings are resolved in this study: primarily, flapping wings less than 3 in. in length produce loads and deformations that are difficult to measure in an accurate and nonintrusive manner. Furthermore, the synchronization of the load measurement system, the vision-based wing deformation measurement system, and the flapping mechanism is demonstrated. Intensive data analyses are performed to extract useful information from the measurements in both air and vacuum.

Deformation behavior of beta-titanium alloys

Abstract: The cold workability of four solution-treated beta-titanium alloys was determined and related to the initial substructure. Two alloys (TIMETAL-LCB and Ti-15-3), which retained a well-developed subgrain structure after solution treatment, exhibited excellent workability, while those alloys which did not (VT22 and TC6) exhibited inferior ductility. The difference in workability was explained in terms of the variation in strain-accommodation mechanism. Other factors that exacerbated the observed low ductility of the latter two alloys were also identified. These included the occurrence of deformation-induced martensite formation and the development of multi-component textures, both of which may lead to localization of deformation at interphase or grain boundaries and subsequent failure.