3,589 research outputs found

    Preliminary weight and costs of sandwich panels to distribute concentrated loads

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    Minimum mass honeycomb sandwich panels were sized for transmitting a concentrated load to a uniform reaction through various distances. The form skin gages were fully stressed with a finite element computer code. The panel general stability was evaluated with a buckling computer code labeled STAGS-B. Two skin materials were considered; aluminum and graphite-epoxy. The core was constant thickness aluminum honeycomb. Various panel sizes and load levels were considered. The computer generated data were generalized to allow preliminary least mass panel designs for a wide range of panel sizes and load intensities. An assessment of panel fabrication cost was also conducted. Various comparisons between panel mass, panel size, panel loading, and panel cost are presented in both tabular and graphical form

    Analytical and experimental investigation of aircraft metal structures reinforced with filamentary composites. Phase 3: Major component development

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    Analytical and experimental investigations, performed to establish the feasibility of reinforcing metal aircraft structures with advanced filamentary composites, are reported. Aluminum-boron-epoxy and titanium-boron-epoxy were used in the design and manufacture of three major structural components. The components were representative of subsonic aircraft fuselage and window belt panels and supersonic aircraft compression panels. Both unidirectional and multidirectional reinforcement concepts were employed. Blade penetration, axial compression, and inplane shear tests were conducted. Composite reinforced structural components designed to realistic airframe structural criteria demonstrated the potential for significant weight savings while maintaining strength, stability, and damage containment properties of all metal components designed to meet the same criteria

    Introduction to the adhesive bonding session

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    Space shuttle unique requirements call for the development of a specific adhesive system to reliable attach reusable surface insulation. A low density foam system has been developed that provides strain isolation from the support structure and remains structurally stable in space shuttle thermal environment. Surface preparation and its stabilization by an adhesive primer system are the most important factors in preventing corrosion from reducing the reliability and durability of the adhesive bonding component

    Nanoscale periodicity in stripe-forming systems at high temperature: Au/W(110)

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    We observe using low-energy electron microscopy the self-assembly of monolayer-thick stripes of Au on W(110) near the transition temperature between stripes and the non-patterned (homogeneous) phase. We demonstrate that the amplitude of this Au stripe phase decreases with increasing temperature and vanishes at the order-disorder transition (ODT). The wavelength varies much more slowly with temperature and coverage than theories of stress-domain patterns with sharp phase boundaries would predict, and maintains a finite value of about 100 nm at the ODT. We argue that such nanometer-scale stripes should often appear near the ODT.Comment: 5 page

    Swine Diets Utilizing Wheat

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    Previous trials have suggested that, when diets were supplemented at the same level and either corn or wheat was used in the same amount as the grain, pig gains were similar. However, pigs fed corn diets were more efficient in terms of both feed use and cost per pound of grain. Wheat diets supplemented at lower levels or assess the value of wheat\u27s higher protein level relative to corn and fed with or without supplemental lysine did not support satisfactory pig performance in terms of gain, feed efficiency or feed cost. Results of these trials suggested that an intermediate level of protein supplementation for wheat should be investigated. The trial reported here was designed with that objective

    Wheat in Swine Finishing Rations

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    The objectives of the trial reported here were: 1. To compare the performance of pigs fed rations with the same proportions of grain and supplement but with the grain corn in one rations and wheat in another ration. 2. To assess the possible feeding value of wheat\u27s greater protein content by use of an all wheat ration in which there was a lower level of supplemental protein. 3. To assess the value of lysine in wheat rations by the effition of lysine to the same ration as used for comparison 2 (above)

    Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft. Volume 1: Technical summary

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    The horizontal stabilizer of the 737 transport was redesigned. Five shipsets were fabricated using composite materials. Weight reduction greater than the 20% goal was achieved. Parts and assemblies were readily produced on production-type tooling. Quality assurance methods were demonstrated. Repair methods were developed and demonstrated. Strength and stiffness analytical methods were substantiated by comparison with test results. Cost data was accumulated in a semiproduction environment. FAA certification was obtained

    Full-scale testing, production and cost analysis data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

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    The development, testing, production activities, and associated costs that were required to produce five-and-one-half advanced-composite stabilizer shipsets for Boeing 737 aircraft are defined and discussed

    Design, ancillary testing, analysis and fabrication data for the advanced composite stabilizer for Boeing 737 aircraft, volume 2

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    Results of tests conducted to demonstrate that composite structures save weight, possess long term durability, and can be fabricated at costs competitive with conventional metal structures are presented with focus on the use of graphite-epoxy in the design of a stabilizer for the Boeing 737 aircraft. Component definition, materials evaluation, material design properties, and structural elements tests are discussed. Fabrication development, as well as structural repair and inspection are also examined
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