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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Vertical steel tubular pins restore the shear strength of honeycomb panels and improve the quality of the repaired panel. New repair method eliminates diagonal pins. Vertical pins are welded to face sheets, forming ''Vierendeel Truss'' arrangement to transmit shear loads.
Projectile penetration characteristics of sandwich structures with honeycomb cores
Inflatable honeycomb panel element for lightweight structures usable in space stations and other construction
Experimental data and performance of honeycomb rotor shroud configuration to improve stall margin of 0.5 hub tip ratio single stage compressor
Flow distribution data for solid and honeycomb rotor shrouds to improve stall margin of 0.5 hub tip ratio single stage compressor
Vibration properties of ring stiffened honeycomb cylinders
Lightweight resin fiber glass honeycomb sandwich structure fabrication and comparison with aluminum structures for planetary probes
Method for honeycomb panel bonding by thermosetting film adhesive with electrical heat means
Technique for making foldable, inflatable, plastic honeycomb core panels for use in building and bridge structures, light and radio wave reflectors, and spacecraft
Fabrication of tantalum alloy honeycomb core structure for lithium cooled reactor
Determination of efficiency of solar absorption of honeycomb structure attached to collecting base surface on which incoming solar energy impinges directly on base surface
The materials selected for the production of extremely lightweight honeycomb sandwich panels are discussed. The resin selected for the first core and face sheet fabrication was Monsanto RS6234 polyimide. The fiber selected for core manufacture was Hercules HT-S, and for face sheets, Hercules HM-S; these selections are discussed.
A study has been initiated to determine the effects of elevated-temperature exposure on the room-temperature mechanical properties of titanium honeycomb-core sandwich panels fabricated by brazing or spot diffusion bonding. Only flatwise tensile properties following exposure have been determined to date. Preliminary results indicate very little change in the flatwise tensile strength of sandwich panels fabricated by spot diffusion bonding following exposures of 10,000 hr at 600 and 800 F and 1000 hr at 1000 F. Titanium panels fabricated by using a Ti-Zr-Be braze alloy are susceptible to oxidation at elevated temperature and experience flatwise tensile strength degradation after continuous exposures of 7500 hr at 600 F, 1000 hr at 800 F, and less than 100 hr at 1000 F. It is possible that the exposure life of the brazed panels may be substantially increased if the panel edges are sealed to prevent oxidation of the braze alloy.
A brazed titanium honeycomb sandwich system for supersonic transport wing cover panels provides the most efficient structure spanwise, chordwise, and loadwise. Flutter testing shows that high wing stiffness is most efficient in a sandwich structure. This structure also provides good thermal insulation if liquid fuel is carried in direct contact with the wing structure in integral fuel tanks.
Three aluminum honeycomb sandwich conical shells with a 120 apex angle and a 4.6-m (15.0-ft) base diameter were loaded to failure by a uniform external pressure. The cones differed from one another only in the thickness of their respective face sheets. Test specimen details, test procedure, and test results are discussed. Both buckling and prebuckling data are compared with appropriate theoretical predictions, and good agreement was obtained between test and theory. Extensive imperfection measurements were made and reported on the three cones in the as fabricated condition.
Two techniques reduce fabrication cost and complexity: net surface molding permits ablative insulators with sculptured tapers to be produced over substrate having unpredictable irregularities; subsurface molding results in ablative surface below honeycomb.
Teflon grommet, cast in place, is easily installed and compatible with honeycomb structural integrity. After casting, grommet blank had only minimum hole size; however, opening can be enlarged by drilling to accommodate larger range of cable diameters. Since grommet is installed flush with adjacent mounting surfaces, it cannot fall out.
Adhesive bonding reduces likelihood of skin failure due to excessive forces or torques by utilizing an adhesive to honeycomb skin. Concept is useful in other applications of composites such as aircraft, automobiles, and home appliances.