Showing papers on "Sandwich panel published in 1983"

Damage Tolerance of Fibre Composite Laminates

Abstract: This paper presents a detailed review of the application of fracture mechanics to fibre composite materials. Particular attention is paid to the effects of manufacturing defects, low energy impact damage, holes and through the thickness cracks.

Radiant heating tests of several liquid metal heat-pipe sandwich panels

Abstract: Integral heat pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid (either sodium or potassium) were tested by radiant heating at various heat load levels. The heat pipe panels reduced maximum temperature differences by 31 percent with sodium working fluid and 45 percent with potassium working fluid. Results indicate that a heat pipe sandwich panel is a potential, simple solution to the engine thermal stress problem. Other interesting applications of the concept include: cold plates for electronic component and circuit card cooling, radiators for large space platforms, low distortion large area structures (e.g., space antennas) and laser mirrors.

Sandwich‐Panel Assemblies: Analytical Model

Abstract: A method of two dimensional analysis of sandwich panel assemblies used as main resisting elements of building structures is provided. This method is based on the equivalent wide column frame analogy, with due consideration given to the composite nature of materials and to the nonlinear behavior of the connection system. A simplified structural idealization is adopted to predict the theoretical response of a six story two cell box structure, subject to a series of loading conditions. Theoretical and experimental results compare favorably. The influence of secondary effect of shear deformation, and the effective width of floor beams on the structural response is also taken into account.

Fabrication and Testing of Carbon Fiber, Graphite-Epoxy Panels for Submillimeter Telescope Use

Abstract: An experimental carbon-fiber, graphite-epoxy, aluminum Flexcore sandwich panel roughly 1-m square was made by Dornier System, Friedrichshafen, West Germany. The panel was a pre-prototype of the panels to be used in the dish of the 10-m diameter Sub-Millimeter Telescope, a joint project of the Max-Planck-Institute fur Radioastronomie, Bonn, West Germany, and Steward Observatory, the University of Arizona in Tucson. This paper outlines the fabrication process for the panel and indicates the surface accuracy of the panel replication process. To predict the behavior of the panel under various environmental loads, the panel was modeled structurally using anisotropic elements for the core material. Results of this analysis along with experimental verification of these predictions are also given.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Vibration of Web-Stiffened Foam Sandwich Panel Structures

Abstract: This paper presents free vibration of rectangular web-stiffened foam sandwich panels simply supported at all four edges. The sandwich structure is composed of orthotropic facing and a number of equally spaced identical stiffeners embedded in the polyurethane core. Transverse shear deformations and rotatory inertia are considered in the thick laminate formulation and the free vibration is treated by way of the panel segment method. Equations of motion of stiffeners are solved in connection with plate-beam interface continuity and panel boundary conditions. Natural frequencies and mode shapes are obtained as a result of non-trivial solution of a system of homogeneous equations.

Radiant heating tests of several liquid metal heat-pipe sandwich panels

Abstract: Integral heat pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich construction, were conceived as a means of alleviating thermal stress problems in the Langley Scramjet Engine. Test panels which utilized two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and a liquid metal working fluid (either sodium or potassium) were tested by radiant heating at various heat load levels. The heat pipe panels reduced maximum temperature differences by 31 percent with sodium working fluid and 45 percent with potassium working fluid. Results indicate that a heat pipe sandwich panel is a potential, simple solution to the engine thermal stress problem. Other interesting applications of the concept include: cold plates for electronic component and circuit card cooling, radiators for large space platforms, low distortion large area structures (e.g., space antennas) and laser mirrors.